LECTURE 3LECTURE 3

associate prof. Yevheniya B. Dmukhalskaassociate prof. Yevheniya B. Dmukhalska

BIOGENIC ELEMENTSBIOGENIC ELEMENTS

All matter in the Universe occurs in the form of All matter in the Universe occurs in the form of atoms of a small number of elements. There are atoms of a small number of elements. There are 92 naturally occurring chemical elements in the 92 naturally occurring chemical elements in the Universe.Universe.Almost every one of the chemical elements Almost every one of the chemical elements plays some role in Earth's living systems, plays some role in Earth's living systems, however, ~20 elements account for the vast however, ~20 elements account for the vast majority of material in living systems.majority of material in living systems.

These These biogenic elements are divided into:biogenic elements are divided into: six major biogenic elements (elements found in almost all of six major biogenic elements (elements found in almost all of

Earth's living systems, often in relatively large quantities); Earth's living systems, often in relatively large quantities); five minor biogenic elements (elements found in many of five minor biogenic elements (elements found in many of

Earth's living systems, and/or in relatively small quantities); Earth's living systems, and/or in relatively small quantities); trace elements (essential elements necessary only in very trace elements (essential elements necessary only in very

small quantities to maintain the chemical reactions on which small quantities to maintain the chemical reactions on which life depends, or elements found only a very few of Earth's life depends, or elements found only a very few of Earth's living systems).living systems).

Major Biogenic ElementsMajor Biogenic Elements

CarbonCarbon

HydrogenHydrogen

OxygenOxygen

NitrogenNitrogen

SulfurSulfur

PhosphorousPhosphorous

Minor Biogenic ElementsMinor Biogenic Elements

SodiumSodium PotassiumPotassium MagnesiumMagnesium CalciumCalcium ChlorineChlorine

Biogenic Trace ElementsBiogenic Trace Elements ManganeseManganese IronIron CobaltCobalt CopperCopper ZincZinc BoronBoron AluminumAluminum VanadiumVanadium MolybdenumMolybdenum IodineIodine SiliconSilicon NickelNickel BromineBromine

According to their abundance in the According to their abundance in the organism , biogenic elements can be organism , biogenic elements can be classsified into: classsified into:

TheThe exception of the organically bound exception of the organically bound elements: 90 % human body.elements: 90 % human body.

MacroelementsMacroelements (basic): 10 – 0,1%. (basic): 10 – 0,1%. Trace or microelementsTrace or microelements: 0,1 – 0,0001%.: 0,1 – 0,0001%. Contaminating elements (Contaminating elements (Ultra-traceUltra-trace oror

ultramicroelements): the lest then ultramicroelements): the lest then 0,0001%.0,0001%.

Macroelements (12 elements in total) form up to Macroelements (12 elements in total) form up to 99 % of any organism, and can be further 99 % of any organism, and can be further subdivided into:subdivided into:

a) a group of stable primary elements (1-60 % ofa) a group of stable primary elements (1-60 % of total organism weighttotal organism weight). These are: O,C, H,N,). These are: O,C, H,N, b) a group of stable secondary elements (0.05/1 % b) a group of stable secondary elements (0.05/1 %

of total organism weightof total organism weight). These are Ca, S, Mg, Cl, ). These are Ca, S, Mg, Cl, Na, K, FeNa, K, Fe

Microelements can be divided into three Microelements can be divided into three categories:categories:

a) a) a subgroup of 8 stable elements (less than a subgroup of 8 stable elements (less than 0.05%). These are the elements: Cu, Zn, Mn, Co, 0.05%). These are the elements: Cu, Zn, Mn, Co, B, Si, F, IB, Si, F, I

b) b) a subgroup of approximately 20 elements that a subgroup of approximately 20 elements that are present at conc. of 0.001% and lower.are present at conc. of 0.001% and lower.

c) c) a subgroup of contaminating elements: Their a subgroup of contaminating elements: Their constant excess in the organism leads to disease: constant excess in the organism leads to disease: Mn, He, Ar, Hg, Mn, He, Ar, Hg, Tl, Bi, Al, Cr, Cd.Tl, Bi, Al, Cr, Cd.

According to their physiological According to their physiological importance, biogenic elements are importance, biogenic elements are essential and nonessential.essential and nonessential.

Essential elements can be divided into two Essential elements can be divided into two groups:groups:

a) a) main essential elements, such as Ca, main essential elements, such as Ca, Mg, Na, K, P, S, Cl,Mg, Na, K, P, S, Cl,

they are present in food. They usually play they are present in food. They usually play multiple roles.multiple roles.

b) b) Trace essential elementsTrace essential elements

The general function of minerals and trace The general function of minerals and trace elements can be summarised as follows:elements can be summarised as follows:

Minerals are essential constitutents of skeletal structures Minerals are essential constitutents of skeletal structures such as bones and teeth.such as bones and teeth.

Minerals play a key role in the maintenance of osmotic Minerals play a key role in the maintenance of osmotic pressure, and thus regulate the exchange of water and pressure, and thus regulate the exchange of water and solutes within the animal and human body.solutes within the animal and human body.

Minerals serve as structural constituents of soft tissues.Minerals serve as structural constituents of soft tissues. Minerals are essential for the transmission of nerve Minerals are essential for the transmission of nerve

impulses and muscle contraction.impulses and muscle contraction. Minerals play a vital role in the acid-base equilibrium of the Minerals play a vital role in the acid-base equilibrium of the

body, and thus regulate the pH of the blood and other body body, and thus regulate the pH of the blood and other body fluids.fluids.

Minerals serve as essential components of many enzymes, Minerals serve as essential components of many enzymes, vitamins, hormones, and respiratory pigments, or as vitamins, hormones, and respiratory pigments, or as cofactors in metabolism, catalysts and enzyme activators.cofactors in metabolism, catalysts and enzyme activators.

Organically bound elements Organically bound elements (Organic element)(Organic element)

HYDROGEN

OXYGEN

Structure of waterStructure of waterHydrogen and polar covalent bondsHydrogen and polar covalent bonds

CarbonCarbon

Carbon, although the second most Carbon, although the second most abundant element in living organisms,abundant element in living organisms, accounts for only 0.02% of the mass of accounts for only 0.02% of the mass of the earth’s crust. It is present in the earth’s crust. It is present in carbonatecarbonate minerals, such as minerals, such as CaCOCaCO33 limestone and in fossil fuels, such as limestone and in fossil fuels, such as coal, petroleum, and natural gas. In coal, petroleum, and natural gas. In uncombined form, carbon is found as uncombined form, carbon is found as diamond and graphite.diamond and graphite.

THE CARBON CYCLE IN NATURETHE CARBON CYCLE IN NATURE

Identification of carbonic acid and carbonate ion СО32–:

CO32– + Ba2+ BaCO3 – white sediment;

CO32– + 2Ag+ Ag2CO3 – compound of white color

Ag2CO3 + H2O 2AgOH + H2CO3 (H2O + CO2)2AgOH Ag2O + H2O – brown sediment;

СaCO3 + 2HCl CaCl2 + H2CO3 (H2O + CO2)Ba(OH)2 + CO2 BaCO3 + H2O – white sediment.

NITROGENNITROGEN

Inert diatomic (NInert diatomic (N22) gas plentyful in the ) gas plentyful in the atmosphere (78%), very stable and atmosphere (78%), very stable and unreactive. Nitrogen is an essential unreactive. Nitrogen is an essential element for life, because it is a element for life, because it is a constituent of DNA for genetic coding constituent of DNA for genetic coding and of amino acids making up proteins, and of amino acids making up proteins, some of which are catalytically active some of which are catalytically active enzymesenzymes..

THE NITROGEN CYCLE IN NATURETHE NITROGEN CYCLE IN NATURE

Identification of ammonium salts NН4+:

NH4+ + NаOH Nа+ + H2O + NH3 (ammonia vapor is determined by the

moistened litmus paper) 2K2HgJ4 + 3KOH + NH4OH = 7KJ + 3H2O + O Hg-JHg – NH2

Identification of nitric acid and nitrate ion NO3–:

2NO3– + 3Cu + 8H+ 3Cu2+ + 2NO + 4H2O

2NO + O2 2NO2 – brown vapor of nitrogen oxide;

3Fe2+ + NO3– + 4H+ 3Fe3+ + NO + 2H2O

Fe2+ + NO [Fe(NO)]2+ – compound of a dark-brown color;

s-elementss-elements Alkali metalsAlkali metals are metals found in are metals found in

Group 1 of the periodic table :Group 1 of the periodic table : Li, Na, Li, Na, K, Rb, Cs, and FrK, Rb, Cs, and Fr – –have the smallesthave the smallest ionization energies of all the ionization energies of all the elements because of their elements because of their vvalence-alence-shell electronshell electron has ns has ns1 1 configurationsconfigurations..

MacroelementsMacroelements

SodiumSodiumSodium is the principle cation of the extracellular fluid.Sodium is the principle cation of the extracellular fluid.

FunctionsFunctions 1. In the regulation of acid-base balance.1. In the regulation of acid-base balance. 2. In the maintenance of osmotic pressure of the body 2. In the maintenance of osmotic pressure of the body

fluids.fluids. 3. In the preservation of normal irritability of muscles 3. In the preservation of normal irritability of muscles

and permeability of the cells.and permeability of the cells. The normal serum sodium level is 133-146 mEq/l. The normal serum sodium level is 133-146 mEq/l.

PotassiumPotassiumPotassium is the principal cation of the intracellular fluid.Potassium is the principal cation of the intracellular fluid.

FunctionsFunctions 1. Intracellular cation in acid-base balance.1. Intracellular cation in acid-base balance. 2. In muscle contraction, particularly in cardiac muscle.2. In muscle contraction, particularly in cardiac muscle. 3. Conduction of nerve impulse.3. Conduction of nerve impulse. 4. Cell membrane function.4. Cell membrane function.The normal concentration of potassium in the serum is 3.5–5.5 mEq /l.The normal concentration of potassium in the serum is 3.5–5.5 mEq /l.

MineralsMineralsHalite (salt) Halite (salt) – – NaClNaClSilvinitSilvinit – – NaCl*KClNaCl*KCl

Mirabilite (Glauber's salt) Mirabilite (Glauber's salt) – – NaNa22SOSO44*10 H*10 H22OO NatronNatron NaNa22COCO33*10 H*10 H22OONaNONaNO33 – – Chile saltpeterChile saltpeter

Lepidolite:Lepidolite:KLiKLi1,51,5AlAl1,51,5[AISi[AISi33ОО1010](F, ОН); ](F, ОН);

SpodumeneSpodumene LiAlSi LiAlSi22OO6 6

Lithium Sodium Potassium

Rubidium

Identification reaction on the alkali cationsIdentification reaction on the alkali cations – – coloration the flame under the following colorcoloration the flame under the following color: : 

LiLi++ – – crimson-redcrimson-redNaNa++ – – yellowyellowKK++, Rb, Rb++ andand Cs Cs++ – – violetviolet  

The Alkaline Earth Metals (Group The Alkaline Earth Metals (Group 2A)2A)

The alkaline earth elements in group 2The alkaline earth elements in group 2 AA - - Be, Mg, Ca, Sr, Ba, and RaBe, Mg, Ca, Sr, Ba, and Ra - - are similarare similar to the alkali metals in many respects. to the alkali metals in many respects. They differ, however, in that they haveThey differ, however, in that they have nsns22 valence-shell electron configurations valence-shell electron configurations and can therefore lose twoand can therefore lose two electrons in electrons in redoxredox reactions. Alkaline earth metals reactions. Alkaline earth metals are thus powerful reducing agents and are thus powerful reducing agents and form ionsform ions with a with a +2 +2 charge.charge.

CalciumCalcium Calcium is present in the body in the largest amount of all the Calcium is present in the body in the largest amount of all the

minerals present in the body. Calcium comprises 2% of the minerals present in the body. Calcium comprises 2% of the body weight. RBC is devoid of calcium. The normal serum body weight. RBC is devoid of calcium. The normal serum level is 9 – 11 mg percent.level is 9 – 11 mg percent.

Calcium is present in three forms:Calcium is present in three forms: 1. 1. Calcium present in ionic form, serving as an important Calcium present in ionic form, serving as an important

regulator of processes in cell cytoplasm.regulator of processes in cell cytoplasm. 2. Protein bound fraction. (This form is physiologically inert.)2. Protein bound fraction. (This form is physiologically inert.) 3. In combination with citrates. (Protein bound fraction is non-3. In combination with citrates. (Protein bound fraction is non-

diffusible whereas other two fractions are diffusible.)diffusible whereas other two fractions are diffusible.)

Calcium is present in bones in the form of hydroxyapatite: (Ca3(PO4)2)2*Ca(OH)2

Functions of calciumFunctions of calcium 1. Calcium along with phosphorus is essential for 1. Calcium along with phosphorus is essential for

bones and teeth formation.bones and teeth formation. 2. In blood coagulation. Calcium activates the 2. In blood coagulation. Calcium activates the

conversion of prothrombin to thrombin.conversion of prothrombin to thrombin. 3. In enzyme activation. Calcium activates large 3. In enzyme activation. Calcium activates large

number of enzymes such as adenosine number of enzymes such as adenosine triphosphatase (ATPase), succinic dehydrogenase, triphosphatase (ATPase), succinic dehydrogenase, lipase etc.lipase etc.

5. In muscle contraction. 5. In muscle contraction. 6. In normal transmission of nerve impulses. 6. In normal transmission of nerve impulses. 7. In neuromuscular excitability. 7. In neuromuscular excitability.

Qualitative reaction:Qualitative reaction:CaClCaCl22 +(NH +(NH44))22CC22OO44= 2NH= 2NH44Cl + CaCCl + CaC22OO44 ( (precipitatesprecipitates))

MagnesiumMagnesium Biological functionBiological function:: Magnesium is an essential component of bone, Magnesium is an essential component of bone,

cartilage and the crustacean exoskeleton.cartilage and the crustacean exoskeleton. Magnesium is an activator of several key enzyme Magnesium is an activator of several key enzyme

systems (enzymes that catalyse the transfer of the systems (enzymes that catalyse the transfer of the terminal phosphate of ATP to sugar or other terminal phosphate of ATP to sugar or other acceptorsacceptors).).

Through its role in enzyme activation, magnesium (like Through its role in enzyme activation, magnesium (like calcium) stimulates muscle and nerve irritability calcium) stimulates muscle and nerve irritability (contraction), is involved in the regulation of (contraction), is involved in the regulation of intracellular acid-base balance, and plays an important intracellular acid-base balance, and plays an important role in carbohydrate, protein and lipid metabolism.role in carbohydrate, protein and lipid metabolism.

CChlorophyllhlorophyll

МинералыМинералы

emerald

apatite

fluorite

dolomite calcite

gypsum

talk

Identification reaction on the alkaline earth metals by the flame coloration under the following colorcoloration under the following color: Ca2+ - brick redSr2+- crimson redBa2+ - grassy green

Ca2+

Ba2+ Ba2+

Identification reaction on Mg2+:Mg2+ + OH– Mg(OH)2 – white amorphic sediment;Mg2+ + NH4OH Mg(OH)2 + NH4

+;MgCl2 + NH4OH + NaHPO4 + 5H2O MgNH4PO46H2O + 2NaCl – white crystalline sediment;

Identification reaction on Ca2+

СaCl2 + (NH4)2CO3 CaCO3 + 2NH4Cl – white amorphic sediment;

Сa2+ + SO42– CaSO4;

Ca2+ + C2O42– CaC2O4;

K4[Fe(CN)6] + Ca2+ K2Ca[Fe(CN)6] – white sediment;Ca2+ + HPO4

2– CaHPO4 – white sediment;

Obtaining of Р2Ca3(PO4)2+10C+ 6SiO2 = 6CaSiO3 + 10CO + P4

І stage:Ca3(PO4)2 + 3SiO2 3CaSiO3 + P2O5

ІІ stage:2P2O5 + 10C P4 + 10CO

Simple substance phosphorus – Р4.Allotropic modification of a simple phosphorus: white, red, black.

P-elements (macroelements)

PhosphorusPhosphorusFunctionsFunctions

1. Phosphorus along with calcium is essential for bones and teeth1. Phosphorus along with calcium is essential for bones and teeth 2. Buffering action, i.е., phosphate buffers.2. Buffering action, i.е., phosphate buffers. 3. In the formation of high energy compounds, i.е., ATP.3. In the formation of high energy compounds, i.е., ATP. 4. In the synthesis of RNA and DNA.4. In the synthesis of RNA and DNA. 5. In the synthesis of phospholipids.5. In the synthesis of phospholipids. 6. In the synthesis of phosphoproteins.6. In the synthesis of phosphoproteins. Phosphorus is present in the blood as:Phosphorus is present in the blood as: 1. Inorganic phosphorus.1. Inorganic phosphorus. 2. Organic phosphorus.2. Organic phosphorus. The normal serum inorganic phosphorus level 2.5 – 4 mg percent.The normal serum inorganic phosphorus level 2.5 – 4 mg percent. It is higher in children, the value being 4 — 6 mg percent.It is higher in children, the value being 4 — 6 mg percent.

Red phosphorus (left), and white Red phosphorus (left), and white phosphorus stored underwater (right).phosphorus stored underwater (right).

Identification of orthophosphoric acid and phosphate ions PO4

3–:

HPO42– + Ba2+ BaHPO4 – compound of a white color

2PO43– + 3Ba2+ Ba3(PO4)2 – compound of a white color;

2HPO42– + 3Ag+ Ag3PO4 + H2PO4

– – compound of a yellow color;HPO4

2– + Mg2+ + NH4OH MgNH4PO4 + H2O – white crystals;H3PO4 + 12(NH4)2MoO4 + 12HNO3 (NH4)3PO412MoO3 + 12NH4NO3 + 12H2O.

SulfurSulfur

Sulfur is present in three amino acids. Sulfur is present in three amino acids. Methionine, cystine and cysteine and thus Methionine, cystine and cysteine and thus it is present in all proteins in the body. it is present in all proteins in the body. Connective tissue, skin, hair and nails are Connective tissue, skin, hair and nails are especially rich in sulfur. Also thiamine and especially rich in sulfur. Also thiamine and biotin (member of Vitamin biotin (member of Vitamin ВВ complex) and complex) and coenzyme coenzyme АА contain sulfur in these contain sulfur in these molecules.molecules.

Diet which is adequate in protein meets the Diet which is adequate in protein meets the daily requirement of sulfur.daily requirement of sulfur.

Qualitative teas for Qualitative teas for SOSO442-2-

phosphase ionphosphase ion: : BaBa2+2+ +SO +SO44

2-2- BaSO BaSO44 ((sedimenssedimens))

IodineIodine Biological functionBiological function: Iodine is an integral : Iodine is an integral

component of the thyroid hormones, component of the thyroid hormones, thyroxine and tri-iodo-thyronine, and as thyroxine and tri-iodo-thyronine, and as such is essential for regulating the such is essential for regulating the metabolic rate of all body processes.metabolic rate of all body processes.

Iodine is readily absorbed from the gastro-Iodine is readily absorbed from the gastro-intestinal tract and the surrounding water intestinal tract and the surrounding water by fish and crustacea. Dietary availability by fish and crustacea. Dietary availability and absorption is reduced in the presence and absorption is reduced in the presence of high dietary intakes of cobalt.of high dietary intakes of cobalt.

FluorideFluoride

FunctionsFunctions 1. It gives strength to enamel tissues.1. It gives strength to enamel tissues. 2. It prevents the bacterial action to the 2. It prevents the bacterial action to the

teeth.teeth. 3. Necessary for the health of teeth.3. Necessary for the health of teeth. Fluoride ions inhibits all those enzymes Fluoride ions inhibits all those enzymes

which needs Mg also, i.е., inhibition of which needs Mg also, i.е., inhibition of glycolysis reactions. On enolase, it has the glycolysis reactions. On enolase, it has the maximum inhibition activity.maximum inhibition activity.

Addition of fluoride salts in water is known as Addition of fluoride salts in water is known as fluoridation.fluoridation.

IronIron Total iron content in the body is 3.5 gm. 70 percent of this iron is Total iron content in the body is 3.5 gm. 70 percent of this iron is

present in hemoglobin.present in hemoglobin. Biologically important compounds of iron are hemoglpbin, Biologically important compounds of iron are hemoglpbin,

myoglobin, cytochromes, catalases, peroxidase. In all these myoglobin, cytochromes, catalases, peroxidase. In all these compounds iron is present as heme form or porphyrin form. In compounds iron is present as heme form or porphyrin form. In addition to these iron is present in non-heme form called non-addition to these iron is present in non-heme form called non-heme iron.heme iron.

Non-heme iron is present as ferritin (а stored form of iron) and Non-heme iron is present as ferritin (а stored form of iron) and ransferring (а transport form of iron).ransferring (а transport form of iron).

Functions of ironFunctions of iron 1. As hemoglobin, in the transport of oxygen.1. As hemoglobin, in the transport of oxygen. 2. In cellular respiration, where it functions as essential 2. In cellular respiration, where it functions as essential

component of enzymes involved in biological oxidation such as component of enzymes involved in biological oxidation such as cytpchromes с, сcytpchromes с, с22 а etc. а etc.

d-elements (microelements)

Qualitative teas for Qualitative teas for FeFe3+3+ and Fe and Fe2+ 2+ ionion::

Qualitative teas for Qualitative teas for FeFe2+ 2+ ionion:: FeSOFeSO44 + + KK33[[FeFe(CN)(CN)66]]=K=K22SOSO4 4 + Fe+ Fe33[[FeFe(CN)(CN)66]]2 2

(blue precipitate)(blue precipitate) Qualitative teas for Qualitative teas for FeFe3+3+ ionion:: 4KCN + 4KCN + FeFeCCll33 = K = KCl +FeCl +Fe(CN)(CN)3 3 (red (red

solution)solution) FeClFeCl33 + + KK44[[FeFe(CN)(CN)66]]=KCl=KCl + Fe+ Fe44[[FeFe(CN)(CN)66]]3 3

(blue precipitate)(blue precipitate)

CopperCopperTotal copper content in the human body is 100-150 mg. It is present Total copper content in the human body is 100-150 mg. It is present in almost all the tissues of the body. Liver is the richest source of in almost all the tissues of the body. Liver is the richest source of copper.copper.

FunctionsFunctions1. Copper is an important constituent of certain enzymes such as, 1. Copper is an important constituent of certain enzymes such as, cytochromes, cytochrome oxidase, cataiase, peroxidase, ascorbic cytochromes, cytochrome oxidase, cataiase, peroxidase, ascorbic acid oxidase, uricase, tyrosinase, cytosolic superoxide dimutase, etc.acid oxidase, uricase, tyrosinase, cytosolic superoxide dimutase, etc.2. Necessary for growth and bone formation.2. Necessary for growth and bone formation.3. Necessary for formation of myelin sheaths in the nervous systems.3. Necessary for formation of myelin sheaths in the nervous systems.4. Helps n the incorporation of iron in hemoglobin.4. Helps n the incorporation of iron in hemoglobin.5. Helps in the absorption of iron from Gl tract.5. Helps in the absorption of iron from Gl tract.6. Helps in the transfer of iron from tissues to the plasma. 6. Helps in the transfer of iron from tissues to the plasma. Copper is present in the plasma as ceruloplasmin. The concentration Copper is present in the plasma as ceruloplasmin. The concentration of ceruloplasmin in plasma is 23 – 40 mg percent. The copper of ceruloplasmin in plasma is 23 – 40 mg percent. The copper containing protein in RBC is erythrocuperin, in liver it is containing protein in RBC is erythrocuperin, in liver it is hepatocuperin, and in brain it is cerebrocuperin.hepatocuperin, and in brain it is cerebrocuperin.

Qualitative teas for Qualitative teas for CuCu2+2+

With ammonia water solusionWith ammonia water solusion::

CuCu2+2+ + 4NH + 4NH33 =[Cu(NH =[Cu(NH33))44]]2+2+ ( (blueblue);); By sulfide ionBy sulfide ion, , hydrogen sulfidehydrogen sulfide: :

CuCu2+2+ + S + S2-2- CuS CuS;; black black By potassium hexacianoferrate (By potassium hexacianoferrate (ІІІІ): ): CuCu2+2+ + K + K44[Fe(CN)[Fe(CN)66] = Cu] = Cu22[Fe(CN)[Fe(CN)66] + 4K] + 4K++. .

(Redder is brown sediment)(Redder is brown sediment)

ZincZinc Zinc is an important constituent of pancreas.Zinc is an important constituent of pancreas. FunctionsFunctions 1. Zinc is а constituent of certain enzymes such as carbonic 1. Zinc is а constituent of certain enzymes such as carbonic

anhydrase, carboxypeptidase, alkaline phosphatase, lactate anhydrase, carboxypeptidase, alkaline phosphatase, lactate dehydrogenase, alcohol dehydrogenase, superoxide dehydrogenase, alcohol dehydrogenase, superoxide dimutase, retinene reducthse, DNA and RNA polymerase.dimutase, retinene reducthse, DNA and RNA polymerase.

2. Necessary for taste buds.2. Necessary for taste buds. 3. Necessary for fertility of mice.3. Necessary for fertility of mice. 4. Necessary for tissue repair and wound healing.4. Necessary for tissue repair and wound healing. 5. Necessary for protein synthesis and digestion.5. Necessary for protein synthesis and digestion. 6. Necessary for optimum insulin action as zinc is the 6. Necessary for optimum insulin action as zinc is the

integral constituent of zinc.integral constituent of zinc.

ManganeseManganese Biological functionBiological function: : Manganese functions in the Manganese functions in the

body as an enzyme activator for those enzymes body as an enzyme activator for those enzymes that mediate phosphate group transfer (ie. that mediate phosphate group transfer (ie. phosphate transferases and phosphate phosphate transferases and phosphate dehydrogenases), pyruvate carboxylasedehydrogenases), pyruvate carboxylase

As a cofactor or component of several key As a cofactor or component of several key enzyme systems, manganese is essential for enzyme systems, manganese is essential for bone formation (mucopolysaccharide bone formation (mucopolysaccharide synthesis), the regeneration of red blood cells, synthesis), the regeneration of red blood cells, carbohydrate metabolism, and the reproductive carbohydrate metabolism, and the reproductive cycle.cycle.

CobaltCobalt

Biological functionBiological function:: Cobalt is an Cobalt is an integral component of integral component of cyanocobalamin (vitamin B12), and cyanocobalamin (vitamin B12), and as such is essential for red blood cell as such is essential for red blood cell formation and the maintenance of formation and the maintenance of nerve tissue.nerve tissue.

Although not confirmed, cobalt may Although not confirmed, cobalt may also function as an activating agent also function as an activating agent for various enzyme systems.for various enzyme systems.

Highly toxicHighly toxic elements elements ! ! Hg, Cd, CrHg, Cd, Cr, , Arsenic (As), Lead (Pb) Arsenic (As), Lead (Pb) As all heavy metals, they accumulate As all heavy metals, they accumulate

throughout the food chain, affecting more throughout the food chain, affecting more strongly higher organisms, including man strongly higher organisms, including man at the top of the food "pyramid"at the top of the food "pyramid"

Mercury and Arsenic tend to appear in the Mercury and Arsenic tend to appear in the nature quite spontaneously, originating nature quite spontaneously, originating from some anthropogenic (human) sources from some anthropogenic (human) sources as well as from geologic formations and as well as from geologic formations and released by local chemical conditions.released by local chemical conditions.