1. Biogenic elements. Qualitative reaction for ions of some macro- microelement
2. Complex compound in biological systems. Determination of water hardness.
Biogenic elements. Qualitative reaction for ions of some macro- microelement. Complex compound in biological systems.
Biological role of potassium and sodium
Potassium ions promotes the protein synthesis by ribosomes; number of enzymes require K+ for maximum activity; metabolically supported gradients of Na+ and K+ across the cell membrane are involved in the maintenance of the membrane potential of excitable tissues, which is the vehicle for transmission of impulses in the form of an action potential; K+ ions enhance the function of parasympathetic nervous system and acetylcholine action on the nervous terminals in muscles; K+ ions reduce the exciting influence of ions on muscles; a proper plasma K+ level is essential for the normal heart functioning more precisely for relaxation of miocardium (diastole);
Sodium ions play the main role in regulation of osmotic pressure and retention of water in an organism; sodium chloridum of blood plasma is the main origin of hydrochloric acid formation; Na+ ions take part in the formation of a short-term memory.
Regulation of the Na and K metabolism in organism.
Sodium content in blood plasma is 130-150 mmol/l.
Potassium content in the blood is 3.4-5.3 mmol/l, this is only 2 % of all potassium content in the human body.
Kidneys are the main regulator of body Na+ and normally 98 % of the body loss of Na+ occurs in the urine. If more Na+ is ingested, its excretion in the urine increases. If less Na+ is ingested or if plasma Na+ falls due to any reason, Na+ may totally dissappear from the urine. This is brought about through the aldosteron which increases the tubular reabsorption of Na+ in the distal part of the nephrons.
The various factors can affect the urinary escretion of Na+:
1. When glomerular filtration is broken, the amount of Na+ filtered is smaal, the renal tubules reabsorb all the filtered Na+ resulting in Na+ retention and hypernatriemia.
2. When tubular reabsorption is broken (in chronic renal failure), it resulting in excessive urinary loss of Na+ and hyponatriemia.
3. Severe acidosis aggravates Na+ loss in the urine because the ranel tubules may fail to produce NH3 in sufficient amount to buffer H ions in the tubular lumen; in this way, there arises a defficiency of NH4 ions which could be excreted in the urine in exchange for Na+ ions.
4. Diuresis. Most Na+ is lost in diuretic conditions as diabetes mellitus, diabetes insipidus or after administration of mannitol or urea (osmotic diuretics).
5. Hormones. The main hormones, regulating Na+ metabolism, are mineralocorticoids and atrial natriuretic peptide (ANP). The mineralocorticoids, aldosterone and deoxycorticosterone, increase Na+ reabsorption from the tubular fluid and therefore their excess causes Na+ retention. In addition, these hormones increase the elimination of more K+ and Na+ in the urine. A greater formetion of aldosterone (primary aldosteronism or
The atrial natriuretic peptide is produced y the atrial muscle fibers. It increases the urinary loss of Na+.
The severe decrease of Na+ in the extracellular space may lead to hypovolemia, hypotension, circulatory collapse and syncope.
Patients with Na+ excess show a raised venous pressure, peripheral and pulmonary edema with eventual respiratory failure. Cerebral symptoms may be seen due to hyperosmolality of the plasma.
The main causes of hyperkaliemia are:
1. Release of cellular K+ from muscle tissue (hard traumas), in intravascular hemolysis, after extensive surgical operations.
2. Renal failure – the K+ secretion by the distal tubules is decreased and retention of K+ takes place.
3. Chronic dehydration and shock (associated with decreased formation of urine and K+ retention).
4. Acidosis – H+ ions displace K+ ions from the cells.
5. Addison’s disease.
Symptoms of hyperkaliemia are exerted mostly on the heart and nervous systems. When the serum K+ level is above 7 mmol/L, ECG changes are observed, bradycardia and arrhytmias appear. The heart becomes more susceptible to vagal stanstil, and heart may stop in diastole.
Hypokaliemia may be observed in decreased K+ intake (in starvation, malnutrition states such as kwashiorkor), in excessive renal loss (in metabolic alkalosis, using of some diuretics, such as furosemid, in renal tubular disorders, in hyperaldosteronism Iincreased production of aldosterone), in severe vomitting or diarrhea. Symptoms are: anorexia, nausea, muscle weakness and mental depression. Irregular pulse and a fall of blood pressure are observed.
Function of Na+, K+-ATP-ase
Most animal cells maintain intracellular K+ and extracellular Na+ at a relatively high concentration due to the operation of the special transmembrane enzyme which is called Na+, K+-ATP-ase. Na+, K+-ATP-ase use the energy derived from ATP to drive the transport of Na+ and K+ ions against the concentration gradient. The Na+, K+-pump is a prominent example of a primary transporter. Na+, K+-ATP-ase has the molecular weight of about 250000 to 300000 and contains two different types of subunits. The large subunit is the portion of the molecule that is phosphorylated as ATP is hydrolyzed. It has binding sites for Na+, K+ and appears to extend through the entire thickness of the cell membrane. The smaller subunit is a glycoprotein and contains sialic acid as well as glucose, galactose and other hexose residues.
Biological role of Calcium and phosphorus
Calcium forms about 1% of adult body weight. It is the most abundant electrolyte in the human body due to its structural function for the skeleton. Normal serum or plasma calcium level is 2.3-2.75 mmol/l. More than 99% of calcium in the body occurs in bones as its phosphate and carbonate; only 0.03% of the total body calcium occurs in blood. The bone calcium is constantly exchanged with the calcium of interstitial fluid and this process is regulated primarily by the parathyroid hormone, active vitamin D and also by calcitonin.
Milk and milk products are the best dietary sources of calcium. Other good sources are egg yolk, leafy vegetables and hard drinking water. In spite of their high calcium content, some vegetable foods such as spinach contain also oxalates and benzoates and are a poor source of calcium because calcium oxalate and benzoate thus formed are insoluble and are not absorbed.
Functions of calcium in the body:
1. Calcium salts take part in bone and tooth development. Deficient supply of calcium leads to rickets in children and osteomalacia in adults. Sufficient calcium intake must be ensured in early life to build up the skeletal reserves. If this is not done, then there occurs an increased incidence of osteoporosis in old age because at that time deficiency of sex hormones especially in females results in calcium mobilization from bones leading to osteoporosis.
2. The clotting of blood needs calcium ions.
3. By regulating the membrane permeability calcium ions control the excitability of nerves. If plasma ionized calcium level falls markedly, tetany results in which spasms of various muscle groups occur. Death may occur from convulsions or from laryngospasm. An excess of plasma calcium depresses nervous activity.
4. Calcium ions act as a cofactor or activator of certain enzymes. A proteiamely calmodulin is present within cells, which can bind calcium. The calmodulin-calcium complex becomes attached to certain enzymes which ire activated. Such enzymes include adenylate cyclase, Ca2+ ATPase, phosphorylase kinase, myosin light chain kinase, phosphodiesterasc and phospholipase A; this mechanism also is required for the release of acetylcholine at the neuromuscular junctions.
5. Calcium ions take part in the contraction of muscle including heart muscle and are involved in the excitation-conraction coupling mechanism. In increased plasma calcium, heart stops in systole. In addition, a high plasma calcium decreases conduction of cardiac impulses and thus can produce heart block.
6. Calcium ions are responsible for initiating contraction in vascular and other smooth muscles. Calcium ions enter through specific channels just as is the case with cardiac muscle. Drugs that block these channels [Ca2+ channel blockers] have profound effect on the contractility of cardiac and smooth muscle as well as on the conduction of impulses within the heart. These drugs find use in the treatment of angina pectoris, cardiac arrhythmias and hypertension.
7. Calcium is essential for maintaining the integrity of capillary wall. In its deficiency, capillary walls become fragile and there is increased permeability of capillaries.
8. Calcium ions are involved in exocytosis and thus have an importrole in stimulus-secretion coupling in most exocrine and endocrine glands, e.g. the release of catecholamines from the adrenal medulla, neurotransmitters at synapses and histamine from mast cells is dependent upon Ca2+.
9. Some hormones exert their influence through Ca2+. For example, the effect of adrenaline on the liver cells to increase glycogenolysis is partly due to an increased Ca2+ within these cells which is independent of cAMP.
Biological role of phosphorus
An adult body contains
Biochemical functions:
1. Phosphorus is essential for the development of bones and teeth.
2. It plays a central role for the formation and utilization of high-energy phosphate compounds (ATP, GTP, creatine phosphate etc.).
3. Phosphorus is required for the formation of phospholipids, phosphoproteins and nucleic acids (DNA and RNA).
4. It is essential component of several nucleotide coenzymes eg. NAD, NADP, pyridoxal phosphate, ADP, AMP.
5. Several proteins and enzymes are activated by phosphorylation.
6. Phosphate buffer system is important for the maintenance of pH in the blood as well as in the cells.
Role of vitamins and hormones in regulation of phosphorous metabolism
The hormones – calcitriol, parathyroid hormone and calcitonin are the major factors that regulate the plasma phosphorus within a narrow range (1.2-2.2mmol/l). Calcitriol is the biologically active form of vit.D. It acts at 3 different levels (intestine, kidneys and bone). Calcitriol increases the intestinal absorption of calcium and phosphate. Calcitriol along with parathyroid hormone increases the mobilization of calcium and phosphorus from bone.
Calcitriol is also involved in minimizing the excretion of Ca and P through the kidney, by decreasing their excretion and enhancing reabsorption. Calcitonin inhibits the reabsorption of phosphorus in kidneys. Thus, calcitonin decreases the phosphorus content in blood. Parathyroid hormone decreases serum phosphorus and increases urinary PO4 (increase phosphorus excretion in urine).
Calcium
Calcium is present in the body in the largest amount of all the minerals present in the body. Calcium comprises 2 percent of the body weight. RBC is devoid of calcium. The normal serum level is 9 – 11 mg percent.
Calcium is present in three forms:
1. Ionized form.
This form is physiologically active form.
2. Protein bound fraction.
On the far right we see some lamellar bone, looking like strata of geologic layers of earth. Into such bone, cones of cutting blood vessels penetrate. They then organize bone around their path of penetration forming bone in long layered tubes. We see those in cross section on the left. They are called Haversian Tubules (take a wild guess who they are named after).
Cells are seen in layers around a central canal (Haversian Canal). Radiating micro tubules reach out intercommunicating.
Cells within bone (osteo) can make (“blast”) or degrade and remove (“clast”) bone substance. Osteoblasts lay down bone and osteoclasts digest bone. How active is all this? Well, depending on who you are, roughly one third of the bone you had yesterday isn’t the bone you have today.
The layering and bundles of layered tubes are of cells and sheets of tissue made of very tough fiber called bone collagen. A bone with all of its calcium leached out can be tied in a knot. On and through that structure, a very special crystalline form of calcium is formed called hydroxyappetite. That stiffens the bone to make it hard.
Bone gets strength from two things.
1) What it is made from (kind of bone), and
2) How it is shaped and organized.
Hydroxyappetite figures in both aspects of strength. The first is kind of obvious. Some stuff is tougher than other stuff. But shape is very important. Tubes are stronger than rods. Tension and compression struts vastly support structures (look at power towers). As with certain crystals – such as those used in phonographs (remember those) – when pressure is placed on them, they polarize and exhibit an electric charge. A needle jiggling in a plastic track while pressing against a crystal will reflect the jiggling as a fluctuating charge which magnified gives us music – and we listen.
The compression of forces of daily activity on hydroxyappetite gives us zones of charge to which the osteoblasts listen. They respond by putting more bone substance where forces generate such charges. Where such charges fail to form, bone – always being dissolved – wheedles away. The form of bone follows function. In other words, as was spoken by Hypocrites a few years ago, “That which is not used, wastes away.” The paraphrase is, “Use it or lose it.”
This had to be rediscovered when perfected devices which held fractured bone pieces absolutely rigidly, better than ever before … produced poorer healing. Without SOME movement, bone formation is not very good.
Calcium
Calcium is an important substance beyond mere bone structure. In ionic form (the molecular water dissolved form) it is a charged atom as Ca++ which means it has charge that pairs it with negative charged things such as two OH- (hydroxyl) molecules or phosphate as PO4=. In this charged form it is used to regulate, control or initiate processes such as nerve conduction, muscle contraction, hormone release among other things. It is very tightly kept at optimum in the blood – even if that means taking calcium from bones. Calcium is the stuff that leaves water spots on dish ware or which makes bathtub rings when combined with certain substances. That is, it easily precipitates. X-rays of injured or inflamed tissue may show deposits of calcium. That does not mean calcium CAUSED the problem, but more likely that calcium is precipitating due to the problem.
Indeed, the combined levels of Ca++ and PO4= found normally in the blood exceed levels which can be achieved in water without precipitating. Blood is hyper saturated with calcium by means of other substances which stabilize calcium in solution. An interesting complication of this fact to babies – especially preemies – is that IV fluids used to maintain babies (who cannot eat) cannot contain EITHER enough Ca++ OR enough PO4= to sustaieeds. Children can get a baby form of rickets which may look like bone loss with fractures. To get around this, if an IV is needed long term, solutions with high calcium have to be alternated with solutions of high phosphate. If the correct amounts of BOTH were placed in a single solution, the calcium phosphate would solidify in the bottle.
When calcium levels in the blood are off by substantial amounts then something else must be at the core of the matter: low protein, high protein, kidney disorder etc. The people who manage calcium and those other difficult blood salts and kidney function are the ones with tall foreheads, out of control hair and who horde all the back issues of the Journal of Clinical Investigation
Diphosphonates are drugs which deliver dual phosphate molecules. Pairs of phosphates glom onto hydroxyappetite like egg dye on an egg. That tends to “stabilize” the otherwise very rapid turnover of the crystal. When there is a process that draws away calcium, the diphosphonates protect the crystals. But they can get in the way of build up when the process is in the direction of accumulation. Newer more clever chemistries are being used to see if the plusses can be made to outweigh the minuses. The very uneven results seen with these drugs as a class reflects the inconsistency of the application. There is tremendous variation and an experienced professional is needed to know if it is helping or hurting.
Body Distribution of Calcium and Phosphate
There are three major pools of calcium in the body:
– Intracellular calcium: A large majority of calcium within cells is sequestered in mitochondria and endoplasmic reticulum. Intracellular free calcium concentrations fluctuate greatly, from roughly 100 nM to greater than 1 uM, due to release from cellular stores or influx from extracellular fluid. These fluctuations are integral to calcium’s role in intracellular signaling, enzyme activation and muscle contractions.
– Calcium in blood and extracellular fluid: Roughly half of the calcium in blood is bound to proteins. The concentration of ionized calcium in this compartment is normally almost invariant at approximately
– Bone calcium: A vast majority of body calcium is in bone. Within bone, 99% of the calcium is tied up in the mineral phase, but the remaining 1% is in a pool that can rapidly exchange with extracellular calcium.
As with calcium, the majority of body phosphate (approximately 85%) is present in the mineral phase of bone. The remainder of body phosphate is present in a variety of inorganic and organic compounds distributed within both intracellular and extracellular compartments. Normal blood concentrations of phosphate are very similar to calcium.
Fluxes of Calcium and Phosphate
Maintaining constant concentrations of calcium in blood requires frequent adjustments, which can be described as fluxes of calcium between blood and other body compartments. Three organs participate in supplying calcium to blood and removing it from blood wheecessary:
· The small intestine is the site where dietary calcium is absorbed. Importantly, efficient absorption of calcium in the small intestine is dependent on expression of a calcium-binding protein in epithelial cells.
· Bone serves as a vast reservoir of calcium. Stimulating net resorption of bone mineral releases calcium and phosphate into blood, and suppressing this effect allows calcium to be deposited in bone.
This form is physiologically inert.
3. In combination with citrates.
Protein bound fraction is non-diffusible whereas other two fractions are diffusible.
Biological role of magnesium.
Half of magnesium occurs in the inorganic matter of bones and the rest occurs in soft tissues and body fluids. Blood plasma contains 0.8-1.2 mmol/l of Mg.
Nuts, legumes, chlorophyll and whole grains are very good sources of magnesium.
Functions of Mg in the body:
1. It takes part in the formation of complex salts of bones and teeth.
2. It acts as a cofactor for many enzymes.
3. It serves to decrease neuromuscular irritability.
Effects of a high serum Mg2 level – Experimentally, a serum Mg2+ level of 8 mmol/L produces immediate and profound anesthesia and paralysis of voluntary muscles. These effects can be reversed by an intravenous injection of a corresponding amount of Ca2+. Serum Mg2+ tends to rise in renal failure.
Deficiency of Mg may occur in the malabsorptive syndrome, increased renal losses (diuretics, gentamycin intake and primary renal disease), chronic alcoholism, diabetic acidosis, cirrhosis of the liver, primary aldosteronism, hyperparathyroidism, prolonged and severe losses of body fluid and prolonged administration of Mg-free intravenous fluids. Plasma Mg may be lowered after parathyroidectomy (along with hypocalcemia) due to avidity of bones for divalent ions. In acute pancreatitis, Mg may become bound as soaps thus decreasing its plasma level.
Symptoms and signs of hypomagnesemia.
1. Neuromuscular disorders – weakness, tremors, muscle fasciculations and sometimes tetany.
2. Central nervous system disorders – personality changes, delirium, psychosis and coma.
Biological role of iron.
Iron is part of the structure of many important body constituents, e.g. hemoglobin, myoglobin, enzymes like cytochromes, catalase, xanthine oxidase, mitochondrial α-glycerophosphate oxidase, etc. The iron content of hemoglobin is 0.34%.
Dietary sources – Animal sources are the best and include liver, red meat and egg yolk. Of the vegetables, spinach and other leafy vegetables are good sources. Dried fruits also contain appreciable amounts of iron.
Plasma iron transport – Before iron can leave the intestinal mucosal cells, it is first converted to Fe2+ form. On entering the plasma, it is again oxidized to Fe3 form and is taken up by a pink colored protein called siderophilin or transferrin, having a mol. wt. about 80,000. The transfer of iron to the transferrin is catalyzed by a Cu-containing protein, namely ceruloplasmin. One molecule of siderophilin binds 2 atoms of iron. The absorbed iron is utilized to form products such as heme, etc. and the remaining portion is mostly stored in the body as ferritin in the reticuloendothelial cells and hepatocytes. Ferritin is a conjugated protein; its iron is in combination with the protein part of the molecule called apoferritin. Apoferritin has a mol. wt. of about 450,000 and is composed of 24 polypeptide subunits; these form an outer shell within which resides a storage cavity for polynuclear hydrous ferric oxide phosphate. Iron within ferritin molecule occurs as ferric hydroxide-ferric phosphate complex and its iron content may be upto 30%. Ferritin also is present in blood plasma where its level is a good index of iron stores of the body. If iron is in excess, then ferritin molecules aggregate forming hemosiderin (iron content upto 55%). Hemosiderin is stored as microscopically visible golden brown granules because it is insoluble due to its containing a characteristic arrangement of the micelles of Fe(OH)3.
Recently the genes for the human transferrin receptors and ferritin have been discovered and the mechanism of regulation of expression of transfcrrin receptors and intraccllular ferritin in response to the iron supply have been established. When iron is in excess, the synthesis of transferrin receptors is decreased and ferritin production is increased; this favors iron storage. When iron is deficient, then reverse changes occur which lead to a decreased ferritin production that decreases iron storage so that iron can be utilized in the body to a maximum.
Factors increasing iron absorption from the intestine:
1. Conditions associated with increased rate of erythropoiesis.
2. Low body stores of iron
3. Taking ascorbic acid, succinic add, fructose and sorbitol along with iron – Ascorbic acid favors reduction of Fe3+ to Fe2+; the latter is more readily absorbed. The other compounds make complexes with iron and increase its absorption.
4. Intake of inorganic iron.
Factors inhibiting iron absorption:
1. Malabsorption syndromes.
2. Diarrheal diseases.
3. An excess of phosphates, oxalates and phyfic acid – These form complexes with iron which are insoluble and cannot be absorbed. Vegetable foods have an excess of phosphates and interfere with iron absorption.
4. Subtotal gastrectomy.
5. Surgical removal of the upper small intestine.
6. Food intake along with iron.
7. Antacid therapy.
8. Chronic Infections.
The iron deficiency results in anemia – this is of hypochromic, microcytic type. It is the most common type of anemia being specially present in women of child-bearing age and infants below 1 year of age. The RBCs are smaller in size and have less hemoglobin as well as less mean corpuscular volume RBC count is low but hemoglobin level of blood is proportionately still lower. The color index which is hemoglobin as °o of the normal divided by RBC count as % of the normal is therefore below one. In addition to the symptoms which are common to all anemias such as a pale appearance and breath lessness on minor exertion, the patient shows some characteristic features. These include a derangement of epithelial surface such as abnormal nail growth (spoon shaped nails or koilonychia), glossitis, fissures around the corners of the mouth and localized thickening of the mucous lining of the esophagus causing dysphagia (Plummer-Vinson syndrome)
Biological role of iodine , fluoride, copper, zinc, selenium and cobalt.
Iodine
The total body contains about 20mg iodine, most of it (80%) being present in the thyroid gland. The only known function of iodine is its requirement for the synthesis of thyroid hormone mainly thyroxin (T4) and triiodothyronin (T3).
Dietary requirements: 100-150micrograms per day.
Sources: Sea food, drinking water, iodized salt.
Diseases states: Toxic goiter.
Fluoride
Functions:
1.It prevents the development of dental caries.
2.It is necessary for the proper development of bones .
3.It inhibits the activities of certain enzymes.
Dietary requirements: 1-2 mg per day.
Sources: Drinking water.
Diseases states: dental caries, fluorosis.
Copper
Functions:
1. It’s an essential constituent of several enzymes (cytochrome oxidase, catalase, superoxide dismutase etc.)
2. It’s necessary for the synthesis of hemoglobin, melanin and phospholipids.
3. Ceruplasmin has oxidase activity and thereby facilitates the incorporation of ferric iron into transferrin.
4. Development of bone and nervous system (myelin requires Cu).
Dietary requirements:2-3 mg per day.
Sources: Liver, kidney, meat, egg yolk, nuts and green leafy vegetables.
Disease status:
1. Copper deficiency (anaemia).
2. Menke’s disease (defect in the intestinal absorption of copper).
3. Wilson’s disease
Zinc
Functions:
1. It is an essential component of several enzymes (carbonic anhydrase, alcohol dehydrase etc.)
2. The storage and secretion of insulin from the beta – cells of pancreas requires zinc.
3. It is require for wound healing.
4. It is essential for the proper reproduction.
Dietary requirements: 10-15g per day.
Sources: Meat , fish, eggs, milk, nutts.
Disease status:
Zinc deficiency: poor wound healing, anaemia, loss of appetite, loss of taste sensation.
Cobalt
Cobalt is only important as constituent of vit-B12. The functions of cobalt is same as that of vit B12.
Selenium
Functions:
1. Selenium along with vit E, prevents the development of hepatic necrosis and muscular dystrophy.
2. Selenium is involved in maintaining structure integrity of biological membranes.
3. Selenium prevents lipid peroxidation and protect the cells against the free radicals.
4. Selenium binds with certain heavy metals and protects the body from their toxic effects.
Dietary requirements: 60-250 micrograms.
Sources: Liver, kidneys, seafood.
Toxicity: Selenosis is toxicity due to very excessive intake of selenium. The manifestation of selenosis includes weight loss, emotional disturbances, diarrhea, hairloss and garlic odour in breath.
Chlorine is contained in all biological liquids of the organism.
Functions:
1. As a component of sodium chloride, it is essential in acid-base equilibrium:
2. As chloride ion, it is also essential in water balance and osmotic pressure regulation.
3. It is also important in the production of hydrochloric acid in the gastric juice.
4. Chloride ion is important as an activator of amylase
Sources: It is mainly available as sodium chloride
Daily requirement: 5 –
The requirements of NaCI depend on the climate and occupation and on the salt content of the diet. Foods of animal origin contain more NaCI than those of vegetable origin.
Disease state: chloride deficit also occurs when losses of sodium are excessive in diarrhea, sweating; loss of gastric juice by vomiting.
Excretion: it is chiefly eliminated in the urine. Also Cl is excreted in the sweat.
In the organism sulphur exists both as organic and inorganic compounds
Functions:
1. It is present primarily in the cell protein in the form of cysteine and methionine.
2. The cysteine is important in protein structure and in enzymic activity.
3. Methionine is the principal methyl group donor in the body .
4. Sulfur is a constituent of coenzyme A and lipoic acid which are utilized for the synthesis of acetyl-CoA and S-acetyl lipoate, respectively.
5. Sulfur is a component of other organic compounds, such as heparin, glutathione, thiamine, biotin, taurocholic acid, sulfocyanides, indoxyl sulfate, chondroitin sulfate, insulin, penicillin, anterior pituitary hormones and melanin.
Sources:
Sulfur intake is mainly in the form of cystine and methionine present in proteins. Other compounds present in the diet contribute small amounts of sulfur.
Disease state:
1. The serum sulfate concentration is increased in the presence of renal functional impairment, pyloric and intestinal obstruction and leukemia.
2. Marked sulfate retention in advanced glomerulonephritis cause the development of acidosis.
3. An increase in the blood indican concentration (indoxyl potassium sulfate) may occur in uremia.
Excretion: it is excreted in the urine
Complex compound
Coordination compounds are the compounds in which the central metal atom is linked to а number of ions or neutral molecules by coordinate bonds i.е. by donation of lone pairs of electrons by these ions or neutral molecules to the central metal atom е.g. nickel tetracarbonyl, [Ni(CO)4] in which CO molecules are linked to the central nickel atom by coordinate bonds by donating lone pairs of electrons.
If the species formed by linking of а number of ions or molecules by co-ordinate bonds to the central metal atom (or ion) carries positive or negative charge, it is called a complex ion, е.g. [Fe(СN)6]4-, [Cu(NH3)4]2+, [Ag(CN)2]– etc. Hence co-ordination compounds may also be defined as those compounds which contain complexions е.g.
K4[Fe(СN)6], [Cu(NН3)4]SO4, Na[Ag(CN)2] etc.
The branch of inorganic chemistry dealing with the study of co-ordination compounds is known as co-ordination chemistry.
Types of complex compounds There are following three types of complexes:
(i) А complex in which the complex ion carries а net positive charge is called cationic complex, е.g. [Co(NН3)]3+, [Ni(NH3)6]2+ etc.
(ii) А complex in which the complex ion carries а net negative charge is called anionic complex, е.g.
[Ag(CN)2]– , [Fe (CN)6]4-
(iii) А complex carrying no net charge is called а neutral complex or simply а complex, е.g. [Ni(CO)4], [CoC13 (NН3)3] etc.
One central atom:
Ammonia complex [Cu(NH3)4]SO4
Aqua complex [Al(H2O)6]Cl3
Acidic complex K2[PtCl4]
Complex with difference ligands K[Pt(NH3)Cl3]
Cyclic (chelates)
Polycentral compoynds
Chain [Cr(NH3)5 – OH – (NH3)Cr]Cl3
Chelaes (CO)5Mn – Mn(Co)5
Before we take up а study of the different aspects of co-ordination compounds, it is important to know some terms to be used therein. А few of these are briefly described below:
(1) Ligands. In the formation of the coordinate bonds, the anions or the neutral molecules act as the electron-pair donors whereas the central metal ion acts as the electron pair acceptor.
The donor atoms, molecules or anions, which donate а pair of electrons to the metal atom and form и co-ordinate bond with it are called ligands.
The common donor atoms in ligands are nitrogen, oxygen and less common are arsenic and phosphorus. For example, in [Ni(NН3)3]2+, central ion is Ni2+ and ligands are NH3 molecules.
The ligand may contain one or more than one donor atom. If only one donor atom is present in its molecule, which can coordinate, then it is called as unidentate (unidentate means one point of attachment or having “one tooth”, uni = one and dent = tooth). This is also referred to as monodentate. А few examples are: NH3, Н2О and CN-. They mayor may not be ionic but the complex part always contains co-ordinate bonds.
The ligand may contain two donor atoms (i.е. coordinating groups) positioned in such а way that а five or а six membered ring is formed with the metal ion, then it is called bidentate chelating ligand and the ring is called chelate ring and the resulting complex is called а metal chelate. The well known examples of the bidentate ligands are
The complexes formed by Cu (II) and Pt (II) ions with ethylenediamine are metal chelates represented as follows:
The ethylene diamine (еn) has two nitrogen atoms and oxalate ion has two oxygen atoms, which, can link to the metal ion.
Similarly, we may have tridentate, tetradentate, hexadentate and polydentate ligands. The hexadentate ligand, edta, (EDTA) has six donor atoms i.е. two nitrogens and four oxygens (of the carboxylic acid groups) capable of bonding to the metal atom.
Some important characteristics of chelates.
These are as follows:
(1) Chelating ligands form more stable complexes than the monodentate analogs. This is called chelating effect.
(2) Chelating ligands, which do not contain double bonds e.g. ethylenediamine form five membered stable rings. The chelating ligands such as acetylacetone form six membered stable ring complexes.
(3) Ligands with large groups form unstable rings than the ligands with smaller groups due to steric hindrance.
Importance of chelates. Chelates are widely used in industry and laboratory
(1) in the softening of hard water
(2) in the separation of lanthanides and actinides
(
(4) in the estimation of nickel (II), magnesium (II) and copper (II) ions quantitatively.
(2) Coordination number. The total number of monodentate ligands (plus double the number of bi dentate ligands if any) attached to the central metal ion through coordinate bonds is called the coordinatioumber of the metal ion. In other words, coordinatioumber may be defined as the number of co-ordinate bonds formed with the central metal ion by the ligands.
For example, in the complex ions: [Ag(СN)2]-, [Cu(NН3)4]2+ and [Cr(Н2О)6]3+, the coordinatioumbers of Ag, Cu and Cr are 2,4 and 6 respectively. Similarly, in the complex ion, [Fe(C2O4)3]2-, the co-ordinatioumber of Fe is 6 because C2O42- is а bidentate ligand. The more common coordination numbers for metals are 2, 4 and 6 while less common are 3, 5, 7 and 8.
(3) Coordination sphere. The central atom and the ligands which are directly attached to it are enclosed in square brackets and are collectively termed as the coordination sphere. The ligands and the metal atom inside the square bracket behave as а single constituent unit. The ionizable groups are written outside the brackets. For example, in the coordination compounds, [Cu(NH3)4]SO4, the complex ion [Cu(NН3)4]2+, in which Cu2+ is the central metal ion and four NH3 molecules are ligands forms the coordination sphere. Similarly, in К2[Pt Cl6], the complex ion [Pt Cl6]2- in which Рt4+ is the central metal ion and six Сl- ions are the ligands form the coordination sphere of this complex.
(4) Oxidation number or oxidation state. It is а number that represents an electric charge which an atom or ion actually has or appears to have when combined with other atoms е.g., oxidatioumber of copper in [Cu(NH3)4]2+ is +2 but coordinatioumber is 4.
Similarly, the oxidatioumber of Fe in [Fe(СN)6]3- is + 3 but the coordinatioumber is 6.
The method of calculation of oxidatioumber of а metal in а coordination compound or а complex ion is illustrated below with а few examples:
(1) Oxidatioumber of Cu in [Cu (NНЗ)4]SO4. Sulphate ion (SO4 2-) carries charge = – 2. As the complex is neutral, charge on the complex ion should Fе = + 2. As NH3 carries no charge, therefore, charge on copper = + 2 i.е. oxidatioumber of Cu = +2.
(2) Oxidatioumber of Fe in [Fe (СN)6]3-
As each CN ion carries charge = – 1, charge on 6 CN ions = – 6. As total charge on the complex ion = – 4, therefore charge on Fe must be = + 2 i.e. oxidatioumber of Fe = + 2.
(3) Oxidatioumber of Fe in К3[Fe(С2О4)3]. As each К+ ion carries charge = + 1, charge оn 3 К+ ions = + 3. Hence charge on the complex ion = – 3. As each oxalate ion
C2O42- has charge = – 2, charge on the three С2О4 = – 6. Therefore, charge on Fe should be + 3. oxidatioumber of Fe in the given complex = + 3.
(4) Oxidatioumber of Ni in [Ni(CO)4].
Total charge on the complex = 0. As CO carries no charge, charge on Ni should be = 0, oxidatioumber of Ni in the given complex =0.
(5) Charge on the complex ion. The charge carried by а complex ion is the algebraic sum of the charges carried by central metal ion and the ligands coordinated to the central metal ion. For example, in the complex ion, [Ag (СN)2]-, Ag+ ion carries а charge of + 1 and each CN- ion carries а charge of –1. Therefore, the net charge on the complexion [Ag(СN)2]- is +1 +(– 2)= – 1.
Similarly, in the complex ion [Cu (NH3)4]2+, Cu2+ ion carries а charge equal to + 2 and as NH3 molecules are neutral, therefore, the net charge on the complex is + 2.
Various terms discussed above may be illustrated by taking an example of the formation of а complex of CoC13 with NН3 as shown below:
Nomenclature: Coordination compounds are formulated and named according to the system set up by Inorganic Nomenclature Committee of the International Union of pure and Applied Chemistry (IUPAC). According to the latest (1990) IUPAC system, the following rules are observed while writing formulas and naming coordination compounds.
Rules for Formula Writing:
(1) Formula of the cation whether simple or complex is written first followed by that of the аinon.
(2) The coordination sphere is written in square brackets.
(3) The sequence of symbols within the coordination sphere is first the metal atom followed by anionic ligands, theeutral ligands and finally cationic ligands.
[Metal atom, anionic, neutral, cationic ligands]
If there are а number of anionic ligands, they are listed alphabetically according to the first symbol of their formulae. Same principle is followed for neutral ligands or positive ligands.
The formulae of а few complexes are given below:
Na[PtBrCl (NO2)(NН3)]
[Co(H2O)2(NН3)4] Сl
(4) Polyatomic ligands are enclosed in parentheses but all ligands are formulated without any space in between.
(5) The number of cations or anions to be written in the formula is calculated on the basis that total positive charge must be equal to the total negative charge, as the complex as а whole is electrically neutral.
2. Rules for Naming the Coordination Compounds:
(1) Order of naming ions: The positive ion (cation) whether simple or complex, is named first followed by the negative ion (anion). The name is started with а small letter and the complex part is written as one word, е.g.
[Co(NН3)6] C13, hexaamminecobalt (III) chloride.
But the non-ionic and molecular complexes are given one word name
[Co(NO2)(NH3)3], triamminetrinitrocobalt (III)
[PtC14(NH3)2], diamminetetrachloroplatinum (IV).
(2) Naming of ligands: Different types of ligands are named differently as follows:
(i) Negative ligands end in – 1, е.g., СN- (cyano), Сl- (chloro), Br- (bromo), F- (fluorо), NO2- (nitro), ОН– (hydroxo), О2- (охо), SO42-(sulphato), С2О22- (oxalato), NН2- (amido ), NH2- (imido), ONO- (nitrito), NO3- (nitrato), SCN- (thiocyanato), NCS- (isothiocyanato), СН2(NН2)COО– (glycinato)etc.
(ii) Neutral ligands have no special ending: NН3 (ammine), Н2О (aqua), CO (carbonyl), CS (thiocarbonyl) and NO (nitrosyl)
(iii) Positive ligands (which are very few) end in -ium, е.g., NН3+ (hydrazinium), NO+ (nitrosonium), NО2+ (nitronium).
(iv) Organic ligunds. Organic free radicals are given their owames. For example, СН3 (methyl), С2Н5 (ethyl), С6Н5 (phenyl), С5Н5 (cyclopentadienyl).
For organic neutral molecules, their names are used. For example, Р(С6Н5)3, triphenylphosphine;
(v) Unidentate ligands with more than one co-ordinating atoms. It is essential to designate the point of attachment of а ligand by placing the symbol of the donor atom attached after that; name of the groups separated by hyphen. These ligands are called ambidentate ligands е.g., in thiocyanate and nitrite ions, we have two options each.
— SCN, thiocyanate – NО2- nitro
— NCS, isothiocyanate – ONO, nitrite
The Role of Elements in Life Processes
More than 30 elements have a key function in helping plants and animals live and be healthy.
Everything around us is composed of chemical elements. Elements are the basic building blocks of our lives. Elements combine with one another in different proportions to form everything from the air that we breathe, to the wood that we use to build our homes, to our own bodies.
Our bodies use different chemical elements for different functions. For instance, our bodies use calcium to build strong bones and fluorine makes our teeth healthier. As our bodies consume these elements through daily functioning, we have to replace them in order to stay healthy and strong. The greatest source of these elements is through the food we eat. Because some of us do not always eat the right foods, we sometimes have to take dietary supplements, such as vitamins, to assure that we maintain the proper chemical balance in our bodies.
Some of the major elements that our bodies use to function properly are described in the following paragraphs. Some surprising minor elements are also described.
Until recently, aluminum was thought to be useless to life processes. It is now thought to be involved in the action of a small number of enzymes. For a technical explanation: “it may be involved in the action of enzymes such a succinic dehydrogenase and d-aminolevulinate dehydrase (involved in porphyrin synthesis).” I have no idea what that means.
Even if this element is necessary for some life function, the amount necessary is greatly exceeded by our incidental intake through our drinking water, food, deodorants and some antacids. Aluminum is relatively benign, and it is used in food additives and indigestion pills. It has been linked to Alzheimer’s disease and the body has a hard time ridding itself of excess aluminum. Aluminum is somewhat more toxic to plants.
Despite Arsenic’s reputation as a highly toxic substance, this element may actually be necessary for good health. Studies of animals such as chickens, rats, goats and pigs show that it is necessary for proper growth, development and reproduction. In these studies, the main symptom of not getting enough arsenic was retarded growth and development. It is suspected, but not known, that arsenic is necessary . It is thought to be necessary for the functioning of the nervous system and for people to grow properly. Since arsenic is present in our food and water, all humans have some arsenic in their bodies and a deficiency of this element in humans has apparently never been observed. An arsenic trioxide has been approved by the Food and Drug Administration to treat a rare and deadly form of leukemia called acute promyelocytic leukemia, or APL.
At first, boron may seem like an unimportant, uncommon and boring element. But boron is actually required by the body in very small amounts, and is necessary for good health. Though it is commonly known that calcium builds strong bones, boron is also important. Bones are not just the dead, white, stone-like things we see on skeletons. In our bodies bones are constantly breaking down and being rebuilt. They also have a constant blood supply and are very much “alive”. Without small amounts of boron, bones would slowly break down and become brittle.
This element is also necessary to allow the brain to function properly. In fact, boron can increase mental alertness. According to a series of studies recently conducted by the US Department of Agriculture, low boron intakes by humans caused decreased brain activity. The studies showed that people on low boron diets also had lower brain performance on attention and short-term memory tests.
Our bodies also need boron in very small amounts to allow calcium, magnesium and phosphorus to function properly. So in a sense, boron is also necessary for many other body functions and we could not survive without it.
This is another element that is probably not necessary for good health and no deficiency of this element has ever been documented. Bromine is suspected to be an essential trace element in red algae and possibly humans. No specific role for this element in human health has been identified. Bromine is found in the mollusk pigment “royal purple”, but it’s purpose in that pigment is not known.
Mixed opinions on cadmium. While it is definitely believed to not be essential for plant and animal life processes, some believe cadmium is a trace element with some necessary role in life processes. Although its need and use are not currently understood. It is thought to be involved with the metabolism Its status as an essential trace element remains unclear.
Calcium (Ca) – a macronutrient
Calcium is an extremely important element in the human body. It is one of the most abundant elements in our bodies and accounts for 2 to
When we don’t get enough calcium, many things happen in our bodies. It is possible to get leg cramps, muscle spasms, our bones may become brittle and even we may even have an increased risk of getting colon cancer. Also, when we don’t get enough calcium in our diets, our bodies will actually use the calcium that we have stored in our bones. This makes the bones thinner and more brittle. In growing children and teenagers the bones may not develop fully and the person can enter adulthood with brittle bones. Further calcium deficiency can lead to serious problems.
Therefore, it is extremely important to get enough calcium in your diet. Unfortunately, that is not always easy to do. Most Americans don’t get enough from their diets. But eating a good balanced diet, including drinking milk on a daily basis, should get you enough calcium.
The element carbon is perhaps the single most important element to life. Virtually every part of our bodies is made with large amounts of this element. The carbon atom is ideal to build big biological molecules. The carbon atom can be thought of as a basic building block. These building blocks can be attached to each other to form long chains, or they can be attached to other elements.
This can be difficult to imagine at first, but it may help to think about building with Legos. You can think of carbon as a bunch of red legos attached together to form one long chain of legos. Now, you can imagine sticking yellow, blue and green legos across the tops of the red (carbon) legos. These other colors represent other elements like oxygen, nitrogen or hydrogen. As you stick more and more of these yellow, blue and green legos to the red chain, it would start to look like a skeleton of legos with a “spine” of red legos and “bones” of yellow, blue and green legos. This is a lot like the way that big molecules are made in the body. Without carbon, these big molecules could not be built.
Now, virtually every part of your body is made up of these big molecules that are based around chains of carbon atoms. This is the reason we are known as “carbon based life forms”. Without carbon, our bodies would just be a big pile of loose atoms with no way to be built into a person.
Chlorine (Cl) – a micronutrient
Anyone who has ever swallowed a mouthful of water at a swimming pool would probably tell you that chlorine is one of the most unpleasant things they have ever swallowed and they wouldn’t mind if they never ingest chlorine ever again. This element, however, is actually essential for humans to live – we would die without it. Chlorine is found throughout the body; in the blood, in the fluid inside cells and in the fluid between cells.
Along with sodium and potassium, chlorine carries an electrical charge when dissolved in body fluids. This is why these elements are termed “electrolytes”. The electrical charge that these elements carry is what allows nerve cells to work. Chlorine also works with potassium and sodium to regulate the amount of fluids in the body and to regulate pH in the body. This vital element also helps muscles flex and relax normally.
Stomach acid is a compound of hydrogen and chlorine (hydrochloric acid, or HCl). Logically, chlorine is extremely important in allowing us to digest our food properly and to absorb the many other elements that we need to survive. Excessive vomiting can lead to a serious loss of chlorine in the body. This can lead to a dangerous imbalance of pH in the body, which can cause muscle weakness, loss of appetite, dehydration and coma.
It is easy to get enough chlorine from natural, unprocessed foods, and deficiencies of this important element are rare. Most Americans, however, consume massive amounts of salt in their diet. Table salt is a compound of sodium and chlorine (sodium chloride, or NaCl). This means most of us get much more chlorine than we really need.
When we think of chromium, our brains may generate images of everything from the shinny finish on our first bicycle to the brilliant chrome rally wheels on the ’66 Mustang GT. The last thing that comes to mind is a substance that we actually need to eat in order to stay healthy. Chromium, in fact, is an element that is essential to good human health. It does many important things in the body. Most significantly, it is a vital component of a molecule that works with insulin to stabilize blood sugar levels. In other words, it helps our bodies absorb energy from the food we eat and stabilizes the level of energy that we feel throughout the day.
Our bodies need sufficient quantities of chromium to make many of the large biological molecules that help us live. This vital element can also help increase muscle mass while reducing fat mass in our bodies. It helps cells, such as heart muscle cells absorb the energy they need to work properly.
Unfortunately, it is often difficult to get enough chromium in our diets. People who exercise frequently have especially high demands for this element. Scientists estimate that 90% of all Americans don’t get enough chromium from their diet. Foods that are high in chromium include whole grain breads, brown rice, cheese and lean meats. Chromium is also in many (but not all) multi-vitamins and supplements, but the body absorbs chromium much better from food.
Cobalt is another element that is necessary for good human health. While cobalt has no specific function by itself, it forms the core of vitamin B-12. Without cobalt, Vitamin B-12 could not exist. The body uses this vitamin for numerous of purposes. B-12 is necessary for the normal formation of all cells, especially red blood cells. Vitamin B-12 also helps vitamin C perform its functions, and is necessary for the proper digestion of the food that we eat. Additionally, vitamin B-12 prevents nerve damage by contributing to the formation of the protective sheath that insulates nerve cells.
A deficiency of vitamin B-12 can cause our red blood cells to form improperly. This can prevent our red blood cells from carrying enough oxygen from our lungs to the different parts of our bodies, thus causing a condition called anemia. Symptoms of anemia include loss of energy, loss of appetite, and moodiness. B12 deficiency can also cause nerve cells to form incorrectly, resulting in irreversible nerve damage. This situation is characterized by symptoms such as delusions, eye disorders, dizziness, confusion and memory loss.
Unlike other B complex vitamins, vitamin B-12 can be stored in the body. Because of this, it is very easy to get enough of this important vitamin in your diet. Deficiencies of B-12 are rare in young people, but do occasionally occur in adults due to digestive disorders or poor absorption by the digestive system. Strict vegetarians are also at risk of B-12 deficiency, because vegetables do not contain this important vitamin. B-12 is only found in animal sources such as red meat, fish, eggs, cheese and milk. Fortunately for vegetarians, you can also get plenty of vitamin B-12 from most multi-vitamin pills.
Copper is an element that is very important for our good health. Actually, that may be understating the true importance of this element. Copper is critically important for dozens of body functions.
To begin with, copper is a major component of the oxygen carrying part of blood cells. Copper also helps protect our cells from being damaged by certain chemicals in our bodies. Copper, along with vitamin C, is important for keeping blood vessels and skin elastic and flexible. This important element is also required by the brain to form chemicals that keep us awake and alert. Copper also helps your body produce chemicals that regulate blood pressure, pulse, and healing. Current research is looking into other ways copper can affect human health, from protecting against cancer and heart disease, to boosting the immune system.
General symptoms of not getting enough copper in your diet include anemia (a condition in which your blood can’t supply enough oxygen to your body), arthritis (painful swelling of the joints), and many other medical problems.
Copper can be found in dried beans, almonds, broccoli, garlic, soybeans, peas, whole-wheat products, and seafood. Unfortunately, many people do not get enough copper in their diets. Also, eating food rich in fructose (sugars in fruit, and cornstarch) and taking mega-doses of vitamin C for long periods of time can keep your body from absorbing the copper in your food. This lack of copper intake by your body can cause the medical problems mentioned above, or it can even affect your life span.
Fluorine is an element that the body uses to strengthen bones and teeth. This element differs from the other elements that the body needs because we get most of it from the water that we drink, not from the food that we eat. The form of fluorine that normally exists iature, fluoride, is actually added to most drinking water supplies. In areas where fluoride is added to the drinking water, children get up to 70% fewer dental cavities than in areas where the drinking water is low in fluoride. As you may have noticed, it is also added to most brands of toothpaste for its ability to fight cavities.
But this important element is also valuable because it helps the body strengthen the bones in your body. Fluoride is the most important trace element affecting bones and teeth. In fact, fluoride is the only element known to single-handedly stimulate bone growth. Fluoride, along with large quantities of calcium, is a large part of what makes your bones strong. When the body does not receive enough fluoride, bones start to loose calcium, and then become weak and brittle. Fortunately, it is easy for us to get enough fluorine because of the fact that it is added to our drinking water. Other good sources of this key element include seafood, teas and toothpaste.
Germanium is a trace element that some believe is highly beneficial to good human health. In fact, germanium has many important medicinal properties. In the body, germanium attaches itself to oxygen molecules. This has the unexpected effect of making our bodies more effective at getting oxygen to the tissues in our body. The increased supply of oxygen in our bodies helps to improve our immune system. It also helps the body excrete harmful toxins.
The increased supply of oxygen in our bodies caused by germanium has many other exciting effects as well. Taking germanium supplements is effective in treating arthritis, food allergies, elevated cholesterol levels, high blood pressure, and even cancer. Germanium can also be used to control pain in the human body.
Perhaps the most exciting thing about germanium is that it can stimulate the human immune system to fight cancer cells. This is exciting for two reasons. First, and most obvious, it helps fight cancer – one of the most deadly diseases in the world. But more importantly, it is not toxic to human cells. In fact, germanium is completely harmless to human cells, even cancer cells. Since it works by stimulating our immune system, which fights the cancer, it doesn’t damage the rest of the body like many other cancer treatments. Testing of new cancer treatments with germanium are underway, and perhaps we will soon see new, less damaging, cancer treatments using the element germanium.
Hydrogen (H) – a macronutrient
It would be virtually impossible to understate the importance of this element to human life. First of all, water is a compound of hydrogen and oxygen (H2O). We can survive years, or at least months without getting most of the other elements that we need to survive. We can survive weeks without food, but we would die after only a few days without water. Water is incredibly important in our bodies. In fact, almost _ of our bodies are made of water. It dissolves other life-supporting substances and transports them to fluids in and around our cells. It is also a place in which important reactions take place in our bodies. Chemically, water is a remarkable substance and it’s many unique attributes make life possible. Hydrogen is obviously a critical component of water and minute chemical bonds called “hydrogen bonds” are what give water many of its unique attributes.
Also, hydrogen is practically always bound to the carbon that our bodies are constructed of. Without this arrangement, our bodies would be little more than a pile of atoms on the ground. Stomach acid is a compound of hydrogen and chlorine (hydrochloric acid, or HCl). Logically, hydrogen is extremely important in allowing us to digest our food properly and to absorb the many other elements that we need to survive. Finally, many chemical reactions that make life possible involve the hydrogen ion. Without this unique and important element, we simply couldn’t exist.
Iodine is an element that is required in very small amounts by the human body. You are probably already aware of some of the uses of this element. Iodine is found in a purple solution that we often put on scrapes and cuts to help our wounds heal faster by preventing them from getting infected. Also, backpackers and campers often add iodine to river and lake water to make it safe to drink.
But the most important thing about iodine is that it keeps our thyroid gland healthy. Most of the iodine in our bodies is stored in this organ, located in the base of your neck. The thyroid gland uses iodine to make chemicals that affect our growth, the way we development and how we burn the energy that we get from the food we eat. If we don’t get enough iodine in our diets, we can expect to have a loss of energy and to gain weight.
Iodine is found in large amounts in seafood, sea vegetables (for example, kelp), dairy products and iodized salt (table salt). It is easy to get enough of this element in your normal diet, and you probably get more than enough if you eat salty foods(with iodized salts, not salt substitutes) like potato chips or french fires.
The element iron has many functions in the body. This element is used by the body to make tendons and ligaments. Certain chemicals in our brain are controlled by the presence or absence of iron. It is also important for maintaining a healthy immune system and for digesting certain things in the food that we eat. In fact, plays a vitally important part of how our body obtains energy from our food.
The iron we obtain from our diet is an essential part of hemoglobin – the part of our blood that carries oxygen. Iron is essential for blood to work efficiently. If we don’t get enough iron in our diets, our blood won’t carry enough oxygen to our bodies and we can feel tired, have decreased alertness and attention span and our muscles may not function properly. This type of iron deficiency is not uncommon among athletes, especially long distance runners. This is frequently the cause of fatigue among these athletes. If the lack of iron in our bodies is severe, we can get “iron deficiency anemia”, which essentially means that our blood won’t carry enough oxygen to our bodies so we can functioormally. Iron deficiency anemia is probably the most common nutritional disease in the world, affecting at least five hundred million people.
Fortunately, it is easy to get enough iron in your food, if you eat a balanced diet. Many foods contain iron, and eating a wide range of foods can help most people meet their needs for this important element.
Magnesium (Mg) – a macronutrient
Magnesium is an element that is required by our bodies for numerous different functions. We need it for the proper growth, formation and function of our bones and muscles. In fact, magnesium and calcium even control how our muscles contract. Magnesium prevents some heart disorders and high blood pressure. Higher intake of magnesium is also associated with improved lung function. Our bodies use it to help convert our food into energy and it helps our bodies absorb calcium and potassium. This important element also helps our brains functioormally. Magnesium even helps to prevent depression.
Magnesium is essential in allowing your body to control insulin levels in your blood. This means that it is very important in the amount of energy that your body has to operate. It is suspected that taking extra magnesium might be beneficial for those suffering from fatigue.
Taking extra magnesium is helpful for treating some medical conditions. Magnesium is sometimes injected into patients’ veins in emergency situations such as an acute heart attack or acute asthma attack. Ion-emergency situations, magnesium is sometimes given to asthma sufferers in a pill form. It relaxes the muscles along the airway to the lungs, which allows asthma patients to breathe easier. Magnesium is effective in treating numerous heart / lung diseases and has been used for over 50 years.
Foods high in magnesium include fish, dairy products, lean meat, whole grains, seeds, and vegetables.
Manganese (Mn) – a micronutrient
Manganese is actually an extremely important element that the body uses for a variety of things. For instance, we use it to make chemicals that help us digest the food that we eat. Manganese also supports the immune system, regulates blood sugar levels, and is involved in the production of energy and cell reproduction. This important element is also important for bone growth. Additionally, manganese works with vitamin K to support blood clotting. Working with the B-complex vitamins, manganese helps to control the effects of stress while contributing to ones sense of well being.
Though it is extremely rare in humans, it is suspected that not getting enough manganese can cause poor bone formation, affect our fertility and the ability for our blood to clot. Birth defects can possibly even result when an expecting mother doesn’t get enough of this very important element. Some researchers are also looking into a link between poor manganese intake and higher skin cancer rates. The fact that manganese is so important to humans, yet deficiencies in humans are so rare, may indicate that humans have evolved ways to make sure that we don’t ever run out of this element in our bodies.
As is the case with most, if not all, elements, we can easily get enough manganese from a good balanced diet. Foods high in manganese include avocados, berries, nuts and seeds, egg yolks, whole grains, green leafy vegetables and legumes (such as peanuts, peas and beans).
Molybdenum (Mo) – a micronutrient
Molybdenum (pronounced mo-lyb-den-um) is necessary for good health, though in extremely small amounts. Molybdenum is found in all tissues of the human body, but tends to be the most concentrated in the liver, kidneys, skin and bones. It is required for the proper function of several chemicals in the human body. Some of these chemicals have the very important job of allowing the body to process the iron and nitrogen in our diets. Molybdenum is believed to be important in helping our cells grow. Also, small amounts of dietary molybdenum have been credited with promoting healthy teeth. Some evidence suggests that molybdenum might reduce the risk of some types of asthma attacks.
A deficiency of molybdenum in our diets can cause mouth and gum disorders and can contribute to getting cancer. A diet high in refined and processed foods can lead to a deficiency of molybdenum, resulting in anemia (lack of oxygen in the blood), loss of appetite and weight, and stunted growth in animals.
The amount of molybdenum in plant foods varies significantly and is dependent upon the mineral content of the soil that the plants were grown in. Nevertheless, the best sources of this mineral are beans, legumes (peanuts and peas), dark green leafy vegetables, and grains. Hard tap water can also supply molybdenum to the diet.
Nickel is known to be an essential trace element for several species of animals. Experimental research shows that when chickens and rats are fed a diet that lacks nickel, they develop liver problems. If they are fed a normal diet, the symptoms do not appear. Animals are not the only ones that need this element to function properly. Bacteria use nickel to make special chemicals called enzymes. These enzymes are necessary for bacteria to function properly.
Though many scientists suspect that nickel is necessary for good human health, it has not been proven. People with certain liver and kidney diseases are known to have low levels of nickel in their bodies. Also, excess nickel in the body is associated with a high incidence of heart disease, thyroid disease and cancer. In both of these cases, the significance of the amount of nickel in the body is unknown. Some scientists think that nickel affects hormones, cell membranes and chemicals called enzymes. Whatever the case, nickel certainly appears to affect human health, even though we do not know exactly how.
Good sources of nickel include chocolate, nuts, fruits and vegetables. Meats are typically low in this interesting element.
Nitrogen (N) – a macronutrient
Nitrogen is another important element. It plays an important role in digestion of food and growth. As you may know, almost 80% of the air we breathe is made up of nitrogen. But humans cannot use the nitrogen in the air we breathe, that nitrogen is in the wrong form. We have to get nitrogen, in a different form, from the food that we eat. Fortunately, there is plenty of nitrogen in food to nourish our bodies.
Nitrogen is found in large amounts in all kinds of food. Spaghetti, salads, breakfast cereal, hamburgers and even cookies have lots of nitrogen in the form that our bodies need. When your body digests this food and makes it into energy, the first step is to remove nitrogen atoms from the molecules in the food. While your body is busy digesting the rest of this food and making it into energy, these nitrogen atoms are already being used to help you grow. One specific time that this is especially important is during pregnancy. When a woman is pregnant, the nitrogen removed from food during digestion is needed to help the fetus to grow properly. By term, the mother and infant will have accumulated over a pound of nitrogen.
It is also worth noting that in the plant kingdom, nitrogen is one of the 3 main elements that make plant life possible. (Potassium and phosphorus are the other two, and you may hear them referred to collectively as N-P-K whenever talking about key plant nutrients.)
It may seem obvious that people need to breathe oxygen to survive, but plants need this element too. Many people think plants “breathe” carbon dioxide and “exhale” oxygen. But in reality, plants also “breathe” oxygen at certain times. Without oxygen, plants could not survive. Without plants, we wouldn’t have food to eat.
It is also worth mentioning that water is a compound of hydrogen and oxygen (H2O) and that water is absolutely necessary for virtually all life as we know it. Water is incredibly important in our bodies. In fact, more than 50% of our bodies are made of water. It dissolves other life-supporting substances and transports them to fluids in and around our cells. It is also a place in which important reactions take place in our bodies. Many people consider water to be the “blood of life”.
When you consider the full importance of oxygen, it becomes clear that this versatile element is the single most important substance to life.
Phosphorus (P) – a macronutrient
Phosphorus is one of the most abundant minerals in the human body, second only to calcium. This essential mineral is required for the healthy formation of bones and teeth, and is necessary for our bodies to process many of the foods that we eat. It is also a part of the body’s energy storage system, and helps with maintaining healthy blood sugar levels. Phosphorus is also found in substantial amounts in the nervous system. The regular contractions of the heart are dependant upon phosphorus, as are normal cell growth and repair.
Since phosphorus is found in almost all plant and animal food sources, a deficiency of this mineral is rarely seen. However, phosphorus deficiency can and does occur, particularly in people who take certain types of antacids for many years. Since phosphorus is important in maintaining the body’s energy system and proper blood sugar levels, it should seem logical that not getting enough of this mineral will affect the energy level in the entire body. Indeed, feeling easily fatigued, weak and having a decreased attention span can be symptoms of mild phosphate deficiency.
It is also worth noting that in the plant kingdom, phosphorus is one of the 3 main elements that make plant life possible. (Potassium and nitrogen are the other two, and you may hear them referred to collectively as N-P-K whenever talking about key plant nutrients.)
The human body must maintain a balance between magnesium phosphorus, and calcium. Excess intake of phosphorus can occur in people with diets high in processed foods, soft drinks, and meats, leading to osteoporosis.
The Recommended Dietary Allowances for phosphorus is 300 milligrams for infants, and between 800 and 1,200 milligrams for adults. It is estimated that Americans ingest on average between 1,500 and 1,600 milligrams of phosphorus per day, almost twice the recommended amount. Foods highest in phosphorus include asparagus, brewers yeast, dairy products, eggs, fish, dried fruit, meats, garlic, legumes, nuts and seeds, and whole grains.
Many antacids, which are widely used for treatment of peptic ulcer disease, gastritis (heart burn) and acid reflux, contain magnesium and aluminum, both of which bind to phosphate, preventing its absorption into the body.
Potassium (K) – a macronutrient
The element Potassium is an extremely important element in the human body. Our bodies are made up of millions of tiny cells, such as brain cells, skin cells, liver cells etc. These cells make up the different organs in our bodies, such as the brain, skin, or liver. Potassium is extremely important to cells, and without it, we could not survive.
Cells are the small building blocks of the human body. In order to work properly, cells need to let things enter and leave them. Cells have many ways by which they can control what (and how much) enters and leaves. Most of the ways that cells do this requires potassium. In fact, without potassium, cells loose control of what can enter and leave them. As you can imagine, this could be very bad. Imagine a nerve cell in your finger for a moment. Normally, it doesn’t really do very much. But when you touch something, it sends messages down a chain of many nerves to your brain that help you determine what it is that you just touched. When a nerve cell does this, it actually pumps out chemicals, which give the message to the next nerve cell and eventually to the brain. Potassium helps control the release of those chemicals. Without potassium, the nerve cell couldn’t send those messages to your brain.
But it is not just nerve cells that depend on potassium. Most, if not all, of our cells depend on it. Just think of it for a minute. Every time you flex your muscles, blink your eyes, yawn in chemistry class, eat lunch, or do anything, you are using potassium. This element is indeed a very important element in our bodies.
It is also worth noting that in the plant kingdom, potassium is one of the 3 main elements that make plant life possible. (Nitrogen and phosphorus are the other two, and you may hear them referred to collectively as N-P-K whenever talking about key plant nutrients.)
Despite selenium’s reputation as a toxic heavy metal, this element is actually very important to good human health. Selenium is an important part of a molecule in the body that protects blood cells from certain damaging chemicals. Together with vitamin E, selenium helps our immune system produce antibodies, which is obviously an immensely important task. Selenium helps keep the pancreas and heart functioning properly. This remarkable element is also needed to make our tissues elastic. Imagine, for instance, if our skin wasn’t elastic; we’d have loose skin draping all over our bodies. It may be cool to have loose clothes draping all over our bodies, but people might make fun of you if you had that much loose skin. Sufficed to say that selenium is a very important element to our bodies.
A deficiency of this vital trace element has been linked to the development of leukemia, arthritis, and other diseases. Researchers have also found that the lower the concentration of selenium in the blood stream, the higher the risk of developing many types of cancer. In fact, some researchers tout selenium as being a powerful cancer-preventing substance. High selenium intake has also been correlated with a dramatically lower incidence of heart disease.
The amount of selenium in food is dependent on the amount of the element in the environment where the food is from. Fish, grains and brazil nuts are considered to be good dietary sources of selenium. However, in the current global marketplace it is difficult to know whether the food you eat comes from selenium-rich or selenium-poor growing areas. As with virtually all elements, it is easy to get enough selenium from a well balanced diet.
If we reflect upon what we all know about silicon for a moment, some of us may recognize silicon as being the key component of sand. Others may think of computer chips; and there is no doubt a few that think of breast implants. Few of us would consider that silicon is something our bodies actually need to be healthy. Silicon is indeed a very common mineral that is required by our bodies. We use it, along with calcium, to grow and maintain strong bones. It is also important to the formation of connective tissues, like ligaments and tendons. Silicon is also important for the growth of hair, skin and fingernails. Unfortunately, despite the fact that silicon is important to the human body, there is comparatively little being done to learn more about why and exactly how it is important for good health.
It is possible that silicon is influential in preventing veins and arteries from getting hard and stiff, though there is no clear understanding of how this element affects artery hardening. Also, it is known that silicon reduces the effectiveness of aluminum in the body. It has been suggested that silicon may be able to delay or prevent Alzheimer’s disease. But once again, it is unclear how silicon may affect this degenerative disease of the brain. A form of silicon is actually a home remedy for problems with weakening bones, painful joints and aging skin, though there is no clear evidence that it actually helps such conditions.
Generally it is quite easy to get plenty of silicon in a normal diet and deficiencies are extremely rare. Foods rich in silicon include whole grain breads and cereals, alfalfa, beets, bell peppers, beans and peas.
Sodium is an element that is vital to human life. Together with potassium and chlorine, it forms a very important part of blood plasma. Without sodium, our cells could not get the nutrients they need to survive. Sodium also allows our bodies to maintain the right blood chemistry and the correct amount of water in our blood. This element also allows our muscles to contract normally. Furthermore, our bodies need sodium to digest the food that we eat. Normal functioning of our nervous system also depends on this important element.
Having the proper amount of sodium in our blood is so important that our bodies have special ways to maintain the right levels of this important element. For instance, if you eat a bag of salty potato chips (salt is actually a compound of sodium and chlorine), your body will soon sense that there is too much sodium in your body. Your body’s first response will be to become thirsty. When you drink water, the sodium in your blood becomes diluted and then your kidneys can remove the excess sodium that you consumed when you ate the salty potato chips.
The foods that most Americans eat are very high in salt content (i.e. potato chips, french fries and popcorn). Salt is really a compound of sodium and chlorine. Therefore, most Americans consume far more sodium than our bodies actually need and it is uncommon that someone would not get enough of this element. One situation that a sodium deficiency can occur, however, is when you sweat a large amount from playing sports or exercising extensively. Your sweat contains a lot of sodium and if you sweat enough, you will loose too much sodium. This can lead to dehydration, weakness and mental confusion. Many athletes drink sports drinks that contain a lot of sodium, like Gatorade, to prevent this from happening.
Sis is an important element that is used in small amounts to help construct virtually all parts of the human body. Sulfur helps protect the cells in our bodies from environmental hazards such as air pollution and radiation. Consequently, sulfur slows down the aging process and extends our life span. Also, sulfur helps our liver function properly, helps us digest the food that we eat and then turn that food into energy. Sulfur is also important for helping our blood clot when we cut or bruise ourselves. Additionally, sulfur is an important part of vitamin B1 and insulin. Interestingly, sulfur is also an important part of a substance that keeps your skin supple and elastic. If you don’t think that is important, just imagine trying to get a date to the homecoming dance with stiff, loose skin hanging all over your body.
Fortunately, there is plenty of sulfur in the food that we eat and it is easy to get enough of this important element in our daily diets. There is no need to worry about getting too much sulfur in your diet. If you get more than your body needs, you just excrete it in your urine. Foods that have a lot of sulfur include meats, fish, dairy products, eggs and garlic.
Tin is possibly an essential element for animals, but no specific role for tin in human health has been identified. Some scientists suspect that extremely small quantities of tin are necessary for some species of animals, such as rats, to grow and develop correctly. Some nutritional supplement retailers suggest that a deficiency in tin can cause baldness in humans, but that has not been proven. Actually, no specific function of any kind for tin has been identified in humans.
Very little has been written on the biological role of titanium. Titanium has no known biological use in humans, although it is known to act as a stimulant. In some plants, titanium is used in chemical energy production. Titanium is used in prosthetics because it won’t react with the biological tissues in the body.
Opinions are mixed about the need for tungsten in plant and animal life processes, although it has been proved to be necessary for certain bacteria. This element has a small function in biological processes. Tungsten is used by certaion-oxygen consuming bacteria in extremely hot ocean environments, such as in hot ocean sediments and deep-sea ocean vents. The bacteria in these environments use tungsten to produce special chemicals called enzymes, which are necessary for certain life processes. Exactly how tungsten is used by these unique and interesting bacteria is quite complex and beyond the scope of this discussion.
It is not known if humans need tungsten for good health. Tungsten is thought to be used by a small number of enzymes in a fashion similar to molybdenum. Here’s how it might be important.
The enzymes described above are in a class of enzymes that perform important tasks for human health. However, the enzymes in this class that humans use incorporate molybdenum, not tungsten, into their structures. Some sources indicate that tungsten is important to humans. But their reasoning is faulty: (a) tungsten is in some of the enzymes of enzyme class “x” (b) some enzymes of class “x” are important to human health (c) therefore, tungsten is important to human health.
Vanadium has recently been declared by some scientists to be essential for good human health. It is believed that vanadium is involved in helping the body convert some foods into energy. It has also been suggested that diabetics may benefit from vanadium when trying to stabilize blood sugar levels. This element is also thought to help bones and teeth form properly.
There is not a great deal of scientific knowledge as to the exact importance of vanadium. Actually, no specific symptoms of vanadium deficiency have been identified in human beings. It is possible that not getting enough of this element may affect the body’s ability to control blood sugar levels and contribute to developing diabetes or hypoglycemia (abnormally low blood sugar levels). Some scientists suspect that a deficiency of this mineral may increase the chance of getting kidney and heart disease. Some research has also shown that vanadium may slow the growth of tumors and provide protection against the development of breast cancer. But more research is clearly needed to determine its exact role in human health.
As is the case with most, if not all, of the biologically important elements, it is easy to get enough of this element from a healthy, balanced diet. Good sources of vanadium include seafood, mushrooms, olives, whole grain breads, carrots and vegetable oils.
Zinc has been recognized as an essential trace element for plants, animals and humans for more than 70 years. Though the average adult body only contains between 2-
Not getting enough zinc can have serious effects on our health. Some of the symptoms of zinc deficiency include hair loss, mental apathy and damage to reproductive organs. Decreased growth rate and impaired mental capacity are other symptoms. Additionally, you can loose most of your senses of taste and smell, develop mental disorders and men can even become impotent without enough zinc.
Many factors affect how well our bodies absorb zinc in the food we eat, and at times it can be difficult to get enough zinc – even from a well balanced diet. Good sources of zinc include whole wheat bread, seafood and other animal meats.
Several other sources (US Geological Survey, United Nations FAO) list additional elements as having a role in plant and/or animal life processes. But no description of that “role” was discovered. Those elements are: Strontium, Lithium, Barium, Rubidium, Cesium, and Platinum (for plants).
Medical Uses of Mercury
The line between alchemy and medicine was not always clear. In 2nd century
In the era before antibiotics, sexually-transmitted diseases were deadly. Some scholars believe that syphilis was the most critical medical problem of the first half of the 16th century. A great number of printed works dealing with syphilis first appeared at the end of the 15th century when it was known by such names as “morbus gallicius,” “the French disease,” “the pox,” and “lues venera.” In the desperate search for a cure, it was almost inevitable that various forms of mercury would be tried. Indeed, the treatment appeared to benefit some patients. While it is unclear whether mercury actually did cure syphilis (some cases of the disease resolve spontaneously), the use of mercury therapy continued into the early 20th century.
The dominating medical use of Hg, (in metallic form and as calomel, Hg2Cl2), in Sweden in the second half of the 19th century indicates that some persons were highly exposed to Hg, mainly for treatment of syphilis, and 0.3-1% of the population of 3.5-5 millions were treated for venereal diseases (10 000-50 000 persons). However, the per capita consumption of Hg was low in
Sublimate (HgCl2 ) is in certain countries still used as an antiseptic for wounds. It was used in large quantities during the World Wars, triggered by the largely increased use of Hg in explosives. Sublimate was also used for preserving wood. Nowadays, the use of Hg in medicine, pharmaceutical products, and gold mining has been prohibited or restricted in industrialized countries, but is still a topic of large concern for the population in many other countries, and needs to be acted upon in order to reduce human exposure. For example, Thimerosal (ethylmercury thiosalicylate) used for preserving vaccines in many countries should be refrained from administering to children, being most vulnerable to Hg. The use of Hg-containing skin lightening soaps, creams, and powder for adults and babies should be ended immediately. This legal production in the EU for export to Africa and
Mercury thermometers
Thermometers contain the less toxic elemental form of mercury and have almost never been a safety issue in peoples’ homes. However, in the 1970’s and 1980’s, workers at the Staco thermometer plant in
