JEEsyllabus.

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Biomolecules
Biochemistry :
The branch of science that deals with the study of the chemical composition and structure of living
organisms and also various changes taking place within them.
Biomolecules : The complex organic molecules which form the basis of life.
Biomolecules build up living organisms and are also required for their growth and maintenances.
The sequence that relates biomolecules to living organisms is
Biomolecules Organelles Cells Tissues Organs Living organism
Biomolecules which form the basis of life are
(i) Carbohydrates, (ii) Proteins, (iii) Nucleic acids (iv) Lipids, (v) Vitamins and Hormones.
Most of the biochemical reactions takes in dilute neutral solutions (pH = 7) at bodytemperature and 1
atmosphere pressure involving complex mechanisms.
The basic structural and function unit of living organisms is the cell.
Glucose molecules supply energy to the cells by undergoing complex and controlled oxidation in
presence of biocatalyst known as enzymes.
In exergonic reactions Gibbs free energy change G is negative. These reactions are spontaneous (G
< 0 spontaneous).
In endergonic reactions Gibbs free energy change G is positive these reactions are non spontaneous
(G > 0 non spontaneous).
Endergonic reactions are made spontaneous by coupling it with exergonic reactions.
Metalbolic process AB G>0 Endergonic nonfeasible
Conversion of S P G < 0 Exergonic feasible
A B
G < 0, feasible
S P

6CO2 + 6H2O
sun light
C6H12O6 + 6O2 G = +2880 kJ. It is a light reaction, it follows a dark reaction
ATP hydrolysis.
ATP
H PO

ADP
H PO

AMP
H PO
Adinocine
Adinosin 3 4 Adinocine 3 4 Adinocine 3 4
1 1
Triphosphate G=31 kJ mole diphosphate G=31 kJ mole monophosphate G=14 kJ mole1

Glucose can be converted into disaccharide, polysaccharides like starch, cellulose or proteins or oils
depending on the nature of plants and the reaction type.
C6H12O6+6O26CO2+6H2O H = 2880 kJ mole1

Carbohydrates
In the beginning carbohydrates are considered as hydrates of carbon because of general formula
Cn(H2O)m.
Rhamnose (C6H12O5) and deoxyribose (C5H10O4) are carbohydrates but not represents the formula
Cn(H2O)m.
They are also called Saccharides due to similar taste like sugar derived from Latin word for sugar
Saccharum.
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Formaldehyde (CH2O), Acetic acid (C2(H2O)2 will not behave like carbohydrates but represents the
formula Cn(H2O)m.
Based on structural evidence and chemical reactivity. They are defined as polyhydroxy aldehydes and
polyhydroxy ketones.
Depending upon their behaviour towards hydrolysis carbohydrates are divided into mono di and
polysaccharides.
Monosaccharides are simple carbohydrates which cannot behydrolysed to simpler carbohydrates.
Ex. (CH2O)n where n = 3 7 (glucose, fructose, ribose, galactose)
Disaccharides give two units of monosaccharides on hydrolysis.
Ex. Sucrose and maltose both have molecular formula C12H22O11.
Oligosaccharides on hydrolysis give 3 to 10 simple monosaccharides disaccarides also can be
considered as oligosaccharides.
Ex. Trisaccharides raffinose
H2O
Glucose + fructose + galactose.
Stachycose (C24H42O21)
H2O
Glucose + fructose + 2 Galactose
Polysaccharides carbohydrates which upon hydrolysis give (more than 10) many monosaccharide
units.
Ex. Starch, cellulose and glycogen (CnH10O5)n.
n = 100 to 3000.
More than 200 monosaccharides are known they are grouped as polyhydroxy aldehydes called
Aldoses and polyhydroxy ketons called as ketoses.
Aldotriose CH2OH CHOH CHO Glyceraldehyde

Aldotetrose CH2OH (CHOH)2 CHO Erythrose, threose

Arabinose, ribose,
Aldopentose CH2OH (CHOH)3 CHO
xylose, lyxose

Glucose, mannose,

galactose, gulose,
Aldohexose CH2OH (CHOH)4 CHO
talose, lolose, allose,

altrose
O
Ketotriose || Dihydroxyacetone
CH2OH C CH2OH
O
Ketoterose || Erytrulose
CH2OH C CHOH CH2OH
O
Ketopentose || Ribulose, Xylulose
CH2OH C (CHOH)2 CH2OH
O
|| Fructose, surbose,
Ketohexose
CH2OH C (CHOH)3 CH2OH tagatoce

Sugars monosaccharides and oligosaccharides are crystalline solids soluble in water and sweet in taste
are called sugars.
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Nonsugars polysaccharides are amorphous solids insoluble in water and taste less called reducing
sugars while others which do not reduced.
Reducing sugar carbohydrates which contain aldehyde or keto group in hemiacetal form reduce
Tollens and Fehlings solution are these reagents are called nonreducing sugars.
Glucose (Dextrose : Grape sugar) 20% in fruits and grapes.
Sucrose and starch on boiling with dil H2SO4 in alcoholic solution undergoes hydrolysis to give glucose.
+
C12H12O11 + H2O
H
C6H12O6 + C6H12O6
sucrose glu cos e fructose
+
H 2 3atm
C12H22O11 + nH2O
393
nC6H12O6
glu cos e

The molecular formula of the glucose is C6H12O6.

Glucose has 5 OH group is conformed by the acylation of glucose.
Acylation of glucose with acetic anhydride or with acylchloride give glucose pentacetate.
CHO (CHOH)4 CH2OH
(CH3 CO)O

CHO (CHOCOCH3 )4 CH2 OCOCH3
Glucose has one carbonyl group. Presence of carbonyl group can be conformed by the reaction with
hydroxylamine or with a molecule of hydrogen cyanide.
CH2OH (CHOH)4 CHO + H2N NHC6H5
D glu cos e phynyl hydroxylamin

HOCH2 (CHOH)4 CH = N NHC6H5

D glu cos e phenyl hydrazone

CH2 OH (CHOH)4 CHO + HCN

D glu cos e

HOCH2 (CHOH)4 CHOHCN

D glu cos e cyanohydrin

Glucose reduces ammonical silver nitrate (Tollens reagent) to metallic silver.

CH2OH(CHOH)4 CHO + Ag2O
CH2OH (CHOH)4 COOH
Gluconic acid

Glucose reduces Fehlings solution to reddish brown cuprous oxide.

CH2OH (CHOH)4 CHO + 2CuO
CH2OH (CHOH)4 COOH + Cu2O
Gluconic acid

Tollens test, Fehlings test confirms that the carbonyl group is CHO aldehyde group.
Bromin water or an alkaline solution of iodine oxidises only the aldehyde group of glucose to gluconic
acid.
Glucose molecule has one primary alcoholic group (CH2OH).
Presence of CH2OH group can be known with nitric acid test.
Glucose with nitric acid gives saccharic acid.
CH2OH (CHOH)4 CHO
HNO3

HOOC (CHOH)4 COOH
Saccharic acid
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Glucose on prolonged heating with HI gives hexane. It indicates that all six carbons of glucose are Pn
linked linearly.
CH2OH (CHOH)4 CHO
HI
CH3 (CH2 )4 CH3
Glucose with phenyl hydrazine gives a osazone called glucosagone it is dihydrazone.
Glucose with concentrated sodium hydroxide first gives a yellow colour and then turns brown and finally
resinifies. This is called is omers action
Glucose with a dilute solution of sodium hydroxide gives a mixture of D-glucose D-mannose,
D-fructose. This is Lobry de Bruyn Van Ekenstein rearrangement.
Fructose and mannose also can give Lobry de Bruyn Van Ekenstein rearrangement.
Due to reversible isomerisation fructose with keto group also can reduce Tollens reagent.
D-glucose and L-glucose differs in the position of OH group at second carbon.
Glucose open chain structure proposed by Bayer.
CHO group of glucose does not respond to Schiffs test and sodium bisulphate and ammonia. This
cant be explained by the open chain structure of glucose.
Pentacetate of glucose does not react with hydroxy lamine though it contains CHO group.
Concentrated solution of glucose at 30C gives -D glucose with melting point 146C and specific
rotation ()D = +111.
Concentrated solution of glucose at above 98C give B-D glucose with the melting point 150C and
specific rotation ()D = +19.2.
D and D forms of glucose differ from each other in stereochemistry at first carbon.
The change in specific rotation of ether form of glucose in aqueous solution to that of equilibrium
mixture is called mutarotation.
ZZZ
X
-D + glucose YZZ ZZZ
X
Z equilibrium mixture + 52.5 36% and 64% YZZ
Z -D glucose +19.2
D and D forms of glucose with methanol and dry HCl gas gives D glucoside and -D-glucoside
respectively.
Glucoside formation involves ring formation with C1 and C5 carbons.
Glucoside formation makes the C1 carbon (anomeric carbon) asymmetric.
-D glucoside and -D glucoside differs in the configuration at C1 carbon are called anomers.
In -D glucoside OH group is at right and in -D glucoside OH grouped left.
Super imposable mirror images are enantiomers.
-D glucoside and -D glucoside are not mirror images of each other and they are not super imposable,
so they are not enantiomers.
Pyranose structure ( or ) is a six numbered cyclic configuration of glucose, it is similar to pyran.
O
Pyran is six numbered ring containing 5 carbons and one oxygen.
Five membered ring structure of glucose is called furanose structure as it is similar to furan.
Glucose is found to occur in pyranose structure.
In Haward structure of glycopyranose the lower thickened edge of the ring is nearest to the viewer.
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The groups projected to the right in Fisher projection are below the plane of the ring and those on the
left are above the plane of the ring.
-D glucopyranose

OH H CH2OH
C
H OH H OH
H
HO H O OH H
H OH HO H
H H OH
CH2OH
The stereochemistry of all sugars is determined with respect to D- or L-glyceraldehyde.
In Fischer projection OH group on C2 is at right (+) configuration is D and OH is on C2 is at left ()
configuration is L.
CHO CHO

H OH HO H

CH2OH CH2OH
R(+) Glyceraldehyde S( ) glyceraldehyde

In tetrose the OH group at C2 and C3 are on the same side. The consider the highest numbered carbon
atom as stereogenic centre.
CHO CHO

H OH HO H
H OH HO H

CH2OH CH2OH
Analogus to Analogus to
D-glyceraldehyde L-glyceraldehyde
CHO CHO

HO H H OH
H OH HO H

CH2OH CH2OH
D - form L - form

D form and L-forms are called diasterioisomers or diastereomers.

Stereoisomers which are not mirror images are called diastereomers.
Disaccharide on hydrolysis give two monosaccharide units may be same or different.
Sucrose glucose + fructose
Lactose glucose + galactose
Maltose glucose + glucose
Reducing and nonreducing nature of disaccharide depends on the position of linkages between the two
monosaccharide units.
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Sucrose C12H22O11 Cane sugar :

It is most common disaccharide widely present in plants.
Sugar cane or beetroot contains sucrose.
Colourless, crystalline, sweet substance with []D = 65.5.
Sucrose is dextro-rotatory, on hydrolysis gives dextro-rotatory glycose []D = +52.5 and Laevorotatory
fructose []D = 92.4.
The mixture of glucose and fructose is Laevorotatory.
Hydrolysis of sucrose involves change in the rotation from D to L, This is called inversion of cane sugar
or mixture is called invert sugar.
Linkage present in sucrose is C1 C2 linkage.
Maltose C12H22O11 :
Maltose is obtained from starch by the hydrolysis process in presence of diastate enzyme produced by
germinated barlyseas.
(C6H10O5)n + n/2 H2O n/2 C12H22O11 (maltose).
Maltose is a reducing sugar contains C-1 to C-4 linkage.

CH2OH CH2OH
O O
H H H H
H H
OH H O OH H
HO OH

H OH H OH

Maltose with the enzyme maltose produced by yeast gives two units of glucose both will have pyranose
form.
Lactose C12H22O11 :
Present in milk and it is known as milk sugar.
It is a reducing sugar on hydrolysis gives
D-galactose and D-glucose.
C12H22O11
emulsion
C6O12O6 + C6H12O6.
Emulsion hydrolyses -glycosidic linkages.
Lactose contains C1 C4 linkage.
CH2OH H OH
O O
HO H
H OH H
OH H H H H
H OH
O
H OH CH2OH

Polysaccharides :
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Starch, cellulose, dexdrin, glycogen are polysaccharides.

Monosaccharides are linked through glycoside linkages in polysaccharides.
Starch or Amylum (C6H10O5)n :
Starch is present in wheat, maize, rice, potatoes, barley, sorghum which are obtained from plants.
Starch is a amorphous while powder insoluble in cold water soluble in boiling water.
Starch solution gives blue colour with iodine in cold condition colour disappears on heating.
Starch on hydrolysis forms D-glucose
n
(C6H10 O5 )n
n / 2 H2O
C12H22 O11
H2O
C6H12O6
2 Maltose D glucose

Starch cannot be oxidised by Tollens reagent or Fehlings solution.

Starch does not forms osazone.
In starch C1 carbon is in glycoside form.
Glycosides are acetyls in which anomeric hydroxyl group is replaced by an alkoxy group.
In glycosides anomeric OH group is replaced by some other groups connected with O, N, S. They are
respectively called their glycoside.
Starch contains polysaccharides amylose and amylopectin.
Natural starch contains 10-20% of amylase and 90-80% of amylopectin.
Amylase water soluble and it contains only D-glucose units they give blue colour with I2 solution.
Amylase contains C1 C4 -glucosidic linkage.
Molecular mass of amylase is 10,000 to 50,000.
Amylopectin branched chain polysaccharide water in soluble.
Amylopectin doesnt give blue colour with I2 solution.
Amylopectin molecule contains 25-30, D-glucose units.
In amylopectin -D-glycosidic link between C1 C4 of the molecule.
Branched chains in amylopectin are due to C1 C6 linkages through oxygen.
Starch a major food material easily hydrolysis in saliva by amylase enzyme to give glucose final
product.
Cellulose (C6H10O5)n :
This is the structural component of vegetable matter.
Wood has 40-50% and cotton has upto 90% cellulose.
It is formed by photosynthesis.
It contains large number of D-glucose units joined by -1, 4 glycosidic linkages.
In the hydrolysis of cellulose gives D-glucose as final product.
Cellulose is digested in ruminant animals like cattle sheep in presence of enzyme cellulose.
Cellulose is a colourless amorphous solid.
Cellulose contains many hydrogen bond which makes the individual stands to align linearly.
It will not reduce Tollens reagent and Fehlings solution.
It doesnt form osazone its molecular weight is about 50,000 5,00,000 or 300-2500 D-glucose units.
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Cellulose doesnt digest in human stomach due to the absence of enzyme cellulose.
Cellulolytic bacteria present in the stomach (rumen) of ruminant mammals like cattle and sheep gives
cellulose it breakdown the cellulose into glucose during digestion.
 Proteins
Amino acids contains both amine group (NH2) and carboxylic acid group (COOH).
Amino acid molecules are linked by forming an amide bond
O

NH C

Carboxylic acid of one molecule reacts with the amino group of another molecule to form amide
bond.
H2O
NH2 CH COOH + H NH CH COOH
| |
R R
O H
|| |
H2N CH C NH C COOH
| Amide bond
(Peptide bond) |
R R
Linkages between amino acids are known a peptide linkages or peptide bonds.
The product obtained from two amino acid molecule through peptide bond is called dipeptide.
Based on number of amino acid molecule in peptide they are called tri, tetra and polypeptides.
Protein from a Greek word proteios mean prime importance.
Proteins are naturally occurring, polypeptides containing 100 to 300 amino acid units.
Silk, hair, skin, connective tissues most of the enzymes, hormone etc are examples for proteins.
In carboxylic acid chain based on the location of NH2 group on the carbon amino acids are
named as , , , .
H2N CH2 COOH -amino acid
H2 N CH2 CH2 COOH -amino acid
H2N CH2 CH2 CH2 COOH -amino acid
Naturally occurring amino acids are more than 700 but important amino acids are 20.
Protein forming amino acids are -amino acid containing a primary amine group except protein a
secondary amine.
Simplex amine acid is glycine Greek meaning sweet.
IUPAC name of glycine is 2-amino ethanoic acid.
Amino acid containing equal number of NH2 and COOH groups are neutral.
Amino acid contains more number of NH2 group it is basic, if it containing more COOH groups it
is acedic.
Amino acids that cannot be synthesized in the body must be supplied through diet are called
essential amino acids.
Non-essential amino acid can be synthesized in the body.
Amino acids are colourless crystalline solids.
Amino acids are highly polar in aqueous solution.
Proton transfers from acid group to amine group to give Zwitter ion or inner salt.
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In Zwitter ion acedic nature is due to NH3+ group and basic nature is due to COO group.
H2O
H2N CH COOH

R
H+
H3N CH COOH (Cation)
H3N CH COO R
OH
R H2N CH COO (Anion)

R
Zwitter ion in acid medium becomes positive ion and in basic medium becomes negative ion.
Dipolar Zwitter ion act as a neutral ion and does not migrate towards anode or cathod at a
particular pH called isoelectric point of the aminoacid.
Isoelectric point of the amino acid depends on the groups present in the amino acids.
For neutral amino acids isoelectric point is in the range 5.5 to 6.3.
Least solubility of amino acid at isoelectric point helps in the separation of different amino acids
obtained from the hydrolysis of protein.
Due to asymmetric (chiral) -carbon all amino acids are optically active except glycine.
In fisher projection D-form of amino acid NH2 group on the right and in L-form NH2 group is on
the left COOH group is on the top in both forms.
COOH COOH
H NH2 H2N H
R R
D - form L - form
Most of the naturally occurring amino acids are with L-configuration.
In a polypeptides free amino group (NH2)
N-terminal residue to the left and acid group is to the right.
Alanyl glycylalanine can be represented as
Ala - Gly - Ala
O O

NH2 CH C NH CH2 C NH CH COOH

N-terminal C-terminal
CH3 CH3

Alanyle glycyl alanine

Shorter peptides are called oligopeptides longer peptides are polypeptides.

Proteins are polypeptides containing many amino acids molecular mass is more than 10,000.
Polypeptides are amphoteric.
Most of the toxins which poisonous substances present in animal and plant venoms are proteins.
Oligopeptides are effective hormones.
Aspertame is a dipeptides which is 160 times sweeter than sucrose.
Aspertame is aspartyl phenylalanine methyl ester.
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CH COOH CH2C6H5

H 2N CH CO NH CH COOCH3

STRUCTURE OF PROTEINS :
Proteins are biopolymers of large number of amino acid linked through peptide bonds or
disulphide bond.
In disulphide linkage S = S
| |
H H
Primary structure of amino acid gives specific sequence of amino acids in polypeptide.
100 amino acid units having 20 different amino acids can combine (20)100 different ways.
Primary structure tells us about peptide linkages and sulphide linkages.
Primary structure is only due to covalent bond linkage.
Secondary structure of protein or polypeptide explains shape and describes conformation of
segments.
Peptide chain folds to limit the possible conformation, to minimise number of hydrogen bonds
and to avoid steric hindrance between R groups.
Secondary structure is due to hydrogen bonds between N and O.
The segment of the protein back bone fold either -helix or pleated sheet or coil conformation.
Tertiary structure is three-dimensional arrangement of atoms in the protein.
It explains extensive coiling or folding to produce a complex.
Quaternary structure defines the structure resulting from the inhalations between the subunits of
polypeptide chains.
The interactions between subunits to give quarlernary structure are
i) Hydrogen bonding
ii) Electrostatic attraction
iii) Hydrophobic interactions
Sub units arrangement in space is given by quarlernary structure.
Protein denaturation involves breaking of tertiary structure of protein.
Proteins with weak interactive bonds can be easily denatured.
Denaturation can be by
i) Changing pH to disrupts hydrogen bonds.
ii) By adding reagent like urea to form strong hydrogen bonds with urea.
iii) Adding detergents like sodium dodecyl sulphate.
iv) Organic solvents associates with non-polar groups to interfere with hydrophobic interactions.
v) Heating or agitation which causes disruption of attractive forces.

AMINO ACIDS DERIVED FROM PROTEINS :

A. Neutral Amino Acids :
1. Glycine (Gly)
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(Aminoacetic acid)
H

H C COOH

NH2
2. Alanine (Ala)
(-Aminopropinoic acid)
H

CH3 C COOH

NH2
3. Valine (Val)
(-Aminiosovaleric acid)
CH3 H

CH3 C C COOH

H NH2
4. Leucine (Leu)
(-Aminoisocaproic acid)
CH3 H H

CH3 C C C COOH

H H NH2
5. Isoleucine (Ileu)
(-Amino--methylvaleric)
CH3 H

CH3 CH2 C C COOH

H NH2
6. Serine(Ser)
(-Amino--hydroxypropionic acid)
H H

HOC C COOH
H NH2
7. Threonine (Thre)
(-Amino--hydroxybutyric acid)
H H

CH3 C C COOH

OH NH2
8. Phenylalanine (Phe)
(-Amino--phenylpropionic acid)
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H H

C C COOH

H NH2
9. Tyrosine (Tyr)
(-Amino-p-hydroxyhydrocinnamic acid)
H H

HO C C COOH

H NH2
10. Tryptophan (Try)
(-Amino--(3-indolyl) propionic acid)
H H

C C COOH

N H NH2

H
11. Proline (Pro)1
(2-Pyrrolidine carboxylic acid)
H2C CH2

H2C CHCOOH
N

H
12. Hydroxyproline (Hpro)1
(4-Hydroxy-2-pyrrolidine carboxylic acid)
HO CH CH2

H2C CHCOOH
N

H
1
Proline and hydroxyproline are imino acids. The nitrogen atom, although joined to the -carbon,
is part of a ring. An imino nitrogen bears only one hydrogen atom but can still take part in the
formation of proteins.
B. Basic Amino Acids:
13. Histidine (His)
(-Amino--4-imidazolylpropionic acid)
H

C
N NH H

H C C CH2 C COOH

NH2
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14. Lysine (Lys)

(, -Diaminocaproic acid)
H

CH2 CH2 CH2 CH2 C COOH

NH2 NH2

15. Arginine (Arg)

(-Amino--guanidinovaleric acid)
H

N H H

H2N C N CH2CH2CH2 C COOH

NH2
C. Acidic Amino Acids :
16. Aspartic acid (Asp)
(Aminosuccinic acid)
O H

HOC CH2 C COOH

NH2
17. Glutamic (Glu)
(-Aminoglutaric acid)
O H

HOC CH2 CH2 C COOH

NH2
D. Sulfur-Containing Amino Acids :
18. Methionine (Met)
(-Amino--methylthiobutyric acid)
H

CH3 S CH2 CH2 C COOH

NH2
19. Cysteine (Cys)
(-Amino--mercaptopropionic acid)
H

HS CH2 C COOH

NH2
20. Cystine (Cys-Scy)
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S CH2 C COOH

NH2
H

S CH2 C COOH

NH2
Vitamins

I. Vitamins
The word vitamin (vital - essential, amines - amino compounds) was proposed by Funk (1912).
He defined it as an accessory food factor which is essential for growth and healthy
maintenance of the body.
They do not provide energy or body building materials.
But they are essential for energy transfer and regulation of metabolism.
Some vitamins form parts of many enzymes. Deficiency of vitamins leads to deficiency disorders.
There are two types of vitamins, namely, fat soluble vitamins and water soluble vitamins.
FAT SOLUBLE VITAMINS :
A, D, E and K are the fat soluble vitamins. They need bile juice for absorption. They are
transported to all parts by lymph.
1. Vitamin-A:
An alcohol (C20H29OH) contain ionone ring and hydrocarbon chain.
Its chemical name is retinol. It is commonly called anti xerophthalimic vitamin.
The main sources of vitamin-A are fish liver oils, milk, butter, egg yolk etc. In plants vitamin-A is
in the form of -carotene (provitamin-A).
In the liver and intestine, -carotene becomes Vitamin-A. It is rich in carrots, green leafy
vegetables etc.
Vitamin-A plays an important role in growth and activity of epithelial tissues and a vital role in
vision.
It is essential for resynthesis of rhodopsin (visual purple) in retina.
Deficiency of Vitamin-A leads to nyctalopia (night blindness), xerophthalmia (dryness of
cornea, swollen eye lids) and keratomalacia (dry and scaly skin).
2. Vitamin-D :
Sterol consisting of 4 rings and a side chain. 3 rings are 6-charbon rings and one ring is
cyclopentane.
The chemical name of vitamin-D is calciferol. It is commonly called antiricketic vitamin or
sunshine vitamin.
The main sources of this vitamin are fish liver oils, milk, butter, egg etc. Mammalian skin can
synthesise vitamin-D in presence of sun light (i.e.. U.V. rays).
Vitamin-D is important for calcium metabolism and it increases the absorption of calcium and
phosphorus from the intestine and is thus necessary for formation of healthy bones and teeth.
Deficiency of Vitamin D in children leads to rickets (bones fails to calcify properly leading to bow
legs, knok-knees, ribs become deformed leading to pigeon breast) and in adults to osteomalacia
(bones become soft and fragile).
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Over doses of Vitamin D (hyper vitaminasis of vitamin D) causes nausea, head ache, kidney
damage, calcification of soft tissues etc.
3. Vitamin E :
Chromone ring with3 methyl groups. It is an unsaturated alcohol.
The chemical name of vitamin E is tocopherol. Its common name is anti-sterelity vitamin. The
sources of E-Vitamin are wheat germs oil, nuts, wheat and maize etc.
This vitamin acts as an anti oxidant. It maintains health and integrity of muscles by controlling the
oxidation of polyunstaturated fatty acids.
Vitamin-E plays an important role in functioning of gonads.
Deficiency of vitamin-E leads to sterelity in males, abortion in females, besides muscular
dystrophy.
4. Vitamin K :
Naphthaquinine derivative.
The chemical name of vitamin K is naphtho quinone.
It is commonly known as antihaemorrhagic vitamin.
It is found in green leafy vegetables, tomato, cheese, eggs, liver etc. Intestinal microbes also synthesise
vitamin K.
It is necessary for the formation of prothrombin, which is required for clotting of blood.
Deficiency of K-vitamin leads to delay in blood clotting process leading to loss of more blood
even from minor wounds.
WATER SOLUBLE VITAMINS :
B and C vitamins are water soluble vitamins. They are directly absorbed by the intestine and are
carried to all parts by blood.
Vitamin-B complex :
Several vitamins have been grouped as B-complex because of their similarities in distribution in
common natural sources.
Most of the vitamins of B-complex acts as co-enzymes.
Main sources of B-complex group of vitamins are liver, milk, eggs, kidneys, fish, cereals, pulses,
nuts, peas, beans, green leafy vegetables etc.
Vitamin B1 (Thiamin) :
Contains pyridine and thiazole molecules (dimethyl amino pyridine).
Cereals, outer brain layers, yeast, milk, green vegetables.
ATP + Bi AMP + Bipyrophosphate Activates carboxylases.
Beri Beri (oedema in leges).
Vitamin B2 ( Riboflavin) :
Flavin derivative
Yeast, vegetables milk, egg white, liver and kidney.
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Two enzymes FMN and FAD are formed, coenzymes for several dehydrogenases.
Dark red tongue, dermatitis, cheilosis, (fissuring at corners of mouth & lips).
Vitamin B3 ( Pentothenic acid) :
Pentothenic acid it is a Dipeptide (C9H17O5N)
Present in all food stuffs
Compound of coenzyme A. Essential for basic reactions in metabolism.
Deficiency case Burning feet.
Vitamin B5 ( Nicotinic acid or Niacin):
Nicotinic acid or Niacin.
Pyridine derivative (Nicotinamide)
Meat, yeast, milk, green leafy vegetables contains B5.
Essential for growth, promoters formation of fats from carbohydrates. Important component of
coenzyme (DPN and NADP).
Pellegra (rough skin) dermatitis, diarrhoea.
Vitamin B6 (Pyridoxine):
Pyridine derivative, pyridoxal phosphate.
Cereals, grams yeast, egg yolk, meat.
Synthesis of fats from carbohydrates. Transportation of amino acids across cell membrane.
Dermatitis, convulsion.
Vitamin B7 (Biotin) or Vitamin H:
Heterocyclic S-monocarboxylic acid. It is called co-enzyme R (C10H16O3N2S).
Yeast, liver, kidney, milk.
Coenzyme for carboxylases. Essential for synthesis of lipids.
Dermatitis. Blood chlesterol increases. Loss of hair, paralysis.
Vitamin B9 ( Folic acid) :
It consists of glutamic acid, para amino benzoic acid and pterin.
Spinach leaf, intestinal bacteria.
Coenzyme, synthesis of RNA. Formation of red cells.
Anaemia, inflammation of tongue, gastro intestinal disorders.
Vitamin B12 ( Cynocobal amine):
Resembles heme. Co3+ is centrally situtated in corrin ring (C63 H88 O14 N14 PCo)
Liver of ox, ping fish etc.
Formation of RBC, synthesis of nucleic acids. Synthesis of lipids from carbohydrates.
Pernicious anaemia hyperglycemia.
Present in all food stuffs
Vitamin C (Ascorbic acid):
Acid. Resemble glucose.
 Biomolecules

Green leafy vegetables, citrous fruits.

Maintenance of redox potentials of cells, coleagen synthesis. Scurvy delay in wound healing
 Nucleic Acids

Nucleic acids are long chain biopolymers of nucleotides with a polyphosphate ester chain.
Proteins have polyamide chain combine with nucleic acids to gives nucleoproteins.
Nucleoproteins present in living cells are
(i) Ribonucleic acid (RNA)
(ii) Deoxyribonucleic Acid (DNA)
DNA on hydrolysis gives deoxyribose, phosphoric acid, pyrimidine and pureine bases.
RNA on hydrolysis gives oxyribose, phosphoric acid, pyrimidine and pureine bases.
These are phosphorus rich biomolecules made of nucleotides.
Altmann gave the term Nucleic acids.
These are of two types known as DNA and RNA.
Deoxyribonucleic Acid (DNA)
It is mainly present in chromosomes and a little amount in Chloroplast and Mitochondria.
It is genetic material in all organisms except in plant viruses.
It is referred as chemical basis of heredity.
Structure:
Watson and Crick gave the structure of DNA in 1953 by considering the above facts. For this
they were given Nobel Prize in 1962.
Each strand shows 5 3 polarity and consists of many nucleotides. They run antiparallel to
each other.
It is tightly coiled in the chromosomes.
Each nucleotide is a deoxyribonucleotide and consists of a pentose sugar Deoxyribose
(C5H10O4), a phosphate and a nitrogen base.
Nucleotide without phosphate is known as Nucleoside.
Alternate arrangement of phosphate and deoxyribose sugar forms the backbone of each DNA
strand. Phospho diester bonds exist between the sugar and phosphate.
A nitrogen base is attached to the sugar by glycosidic bond towards the interior of strand.
Nitrogen bases are of two types known as Purines and Pyrimidines.
Purines are heterocyclic compounds and have two C-N rings. They are Adenine and Guanine.
Pyrimidines are homocyclic compounds and have only one C-N ring. They are Cytosine and
Thymine.
Adenine of one-strand pairs with Thymine of another strand and two hydrogen bonds are formed
between these two.
Similarly Guanine pairs with Cytosine and three hydrogen bonds are formed between these two.
AT/GC ratio varies from species to species.
 Biomolecules

AT/GC ratio is 1.52 in human 0.93 in E.coli.

AT and GC are called as complementary nitrogen base pairs.
Complementary nitrogen base pairs with hydrogen bonds between them form the steps or rings
of the molecule.
The length of DNA molecule is variable. Its diameter is 20A.
Length of each spiral of DNA is 34A. Each spiral has 20 nucleotides with 10 in each strand.
The distance between adjacent nucleotides is 3.4A and the angle between them is 36.
Functions of DNA
It has two functions known as Autocatalysis and Heterocatalysis.
1. Autocatalysis:
Duplication of a DNA molecule into two-daughter DNA molecule is called as Autocatalysis or
Replication.
In this process the two strands of DNA unwind by the action of Endonucleases, which break the
hydrogen bonds between the two strands.
The unwinding starts at one end and advances towards the other end.
Each strands acts as template on which a new strand is synthesised by the action of DNA
polymerase. In this way two daughter DNA molecules are formed which resemble each other.
Since one of the parental DNA strand is retained in each daughter DNA molecule, it is called as
semi conservative mode of replication.
One stand of DNA is synthesized discontinuously in small pieces which are finally joined by
enzyme called DNA ligase to the other continuously chain.
The genetic information of human cell is contained in 23 pars of chromosomes.
Chromosomes is composed by several thousand genes or segments of DNA.
Human gene contains 2.9 billion base pairs.
DNA promotes the synthesis of proteins and regulates various biochemical reactions of the cell.
In this process the DNA template transfers the genetic information in the form of code words to
messenger RNA. This process is called as Transcription that helps in the synthesis of proteins.
Replication takes places at a region of the molecule where the stands separates is called a
replication fork.

DNA
replication (or )

transcription
DNA RNA

translation
Pr oteins
duplication reverse
transcription

Ribonucleic Acid (RNA) :

It is mainly present in ribosomes and small amounts in mitochondria and chloroplasts.
It is synthesised in the nucleous and later released into the cytoplasm.
It is of two types known as genetic and non-genetic RNA.
Genetic RNA is present in many plant viruses such as Tobacco Mosaic Virus (TMV).
Non-genetic RNA is involved in protein synthesis.
 Biomolecules

Structure of RNA :
It is usually single stranded. It is double stranded in some viruses such as Reo virus and Wound
Tumour virus.
Strand is made of many Ribonucleotides. Each nucleotide has a phosphate group, a Ribose
sugar (C5H10O5) and a Nitrogen base.
The nitrogen bases are Adenine, Guanine (Purines) and Cytosine and Uracil (Pyrimidines).
Uracil differs with Thymine in lacking methyl (CH3) group.
Purines and Pyrimidines do not exist in 1: 1 ratio.
Hydrogen bonding is uncommon.
It has 80 to few thousand nucleotides.
Types of RNA :
There are three types of RNA known as messenger RNA, ribosomal RNA and transfer RNA.
1. Messenger RNA:
It has an unfolded linear strand consisting of few hundred nucleotides.
It is synthesised on DNA strand (template). This process is called as Transcription.
It accounts for 5 10% of total cellular RNA.
Its molecular weight is 5,00,000 Daltons.
It is most unstable RNA with a life span of 2 minutes in prokaryotes and up to 4 hours in
Eukaryotes.
It carries protein synthesis information in the form of codons from DNA to ribosomes.
Codons are triplets. A set of three adjacent nucleotides or nitrogen bases on the m-RNA is called
as Codon.
There are 64 codons formed by the four nitrogen bases. Out of these 61 are sense codons and
the remaining 3 are nonsense codons (UAA, UAG and UGA).
The first codon of messenger RNA is AUG or GUG.
UCA on mRNA codes for the amino acid serine and CAG codes for glutamine.
More than one codon can code for the same amino acid.
CUU and CUC can both code both for Leucine.
Codons synonymous and genetic code is degenerate.
Mutations can cause the change in the sequence of amino acids.
Three complimentary nucleotides for recognition of the triplets in m-RNA (anticodon).
The features of genetic code are (i) it is universal (ii) it is commaless (iii) its degenerate (iv) third
base in the codon is not specific.
2. Ribosomal RNA:
It is most stable RNA.
It is single stranded and usually folded to form pseudo helices.
 Biomolecules

At the helices, it shows hydrogen bonding between the complementary nitrogen bases of the
same strand.
It is the largest RNA.
It helps in maintaining the structure of Ribosomes and perhaps involves in protein synthesis.
Transfer RNA:
It is also known as Soluble RNA or Adaptor RNA.
Transfer RNA helps in bringing the amino acids from cytosol to ribosomal surface at the time of
protein synthesis.
Nucleosides and Nucleostides :
Nucleosides :
The molecules in which one of the nitrogen bases (purine or pyrimidine )is bonded with a sugar
molecule is called nucleoside.

Base + Sugar = Nucleoside

Nucleotides :
When the phosphate group is attached to the nucleoside, the compound formed is called
nucleotide.

Base + Sugar + Phosphate = Nucleotide

the sugar in RNA nucleoside is ribose while the sugar in DNA nucleoside is deoxyribose.
Bases :
1 6 7
5
N N
2 4 8
N N9
3
H
PURINES
NH2 O

N N HN N

N N N N
H2N
H H
Adenine(A) Guanine(G)
 Biomolecules

3 4
5
N
2 6
N
1
PYRIMIDINES

O NH2
O
CH3
HN N
HN

O N O N
O N
H H
H
Thymine(T) Uracil (U) Cytosine(C)

5' O
HOH2C Base
N-Glycosidic bond
4' 1'
Ribose sugar
H H
H H
3' 2'
OH OH
Nucleoside from RNA

5' O
HOH2C Base
N-Glycosidic bond
4' 1'
Dioxyribose sugar
H H
H H
3' 2'
OH H
Nucleoside from RNA

O P O CH2 Base
O
O Sugar

OH
 Biomolecules

O
5'
O P O CH2 Base
O
O Sugar

3'
O
+
O P
O O
O P O CH2 Base
O
O
O Sugar Base
5' CH2
O
OH Sugar
3'
OH
5' end of chain 3' end of chain
 Lipids

Lipids: The constituents of animals and plants soluble in organic solvents (ether, chloroform, carbon
tetrachloride, hexane, benzene etc) but insoluble in water are called lipids.
Lipids are naturally occurring carbon compounds related to fatty acids and esters of fatty acids.
Lipids are important dietary components due to their high calorific value.
One gram of lipids yields 9.3 k.cal of heat while one gram of carbohydrate (or) protein yields
4.5 k.cal only.
The common lipids are fats, oils, waxes, steroids, terpens, phospholipids and glycolipids.
The above lipids are stored in adipose tissues and are present in all organism including viruses.
Lipids occur in seeds, nuts and fruits of plants.
Lipids occur in adipose tissues, bone marrows and nervous tissues of animals.
In the living cells lipids are present in cytoplasm and plasma membrane.
In the body lipids are deposited in specialised areas as depots of fat.
Fat depots are formed from food fat, carbohydrates and proteins.
Animal sources of fats are ghee, butter curd and fish oils. These fats contains more saturated fatty acids.
Vegetable sources of fats are ground nut oil, gingerly oil, mustard oil, cotton seed oil, sunflower oil etc. These
fats contains more unsaturated fatty acids.
Depot fats are mixed triglycerides.
Classification and Structures of Lipids:
Lipids are classified into three groups
1) Simple lipids (Homo lipids)
2) Compound lipid (hetero lipids)
3) Derived lipids (obtained from simple and compound lipids)
Simple Lipids:
Simple lipids are alcohol esters of fatty acids which include neutral fats and waxes.
These fatty acids contain even number of carbon atoms and are both saturated and unsaturated carboxylic
acids.
Simple lipids are known as triglycerides (or) triacyl glycerols.
Some simple lipids are solids (or) liquids at room temperature.
Solids are called fats and liquids are called oils.
The structure of simple lipid is
CH2 OCOR1
|
CH OCOR2
|
CH2 OCOR3
R1, R2, R3 = Alkyl groups of fatty acids
R1, R2, R3 = may be same (or) different.
 Biomolecules

Simple neutral lipids:

CH2 OCOC15H31
|
CH OCOC15H31
|
CH2 OCOC15H31
Tripalmi tin (saturated)
In tripalmitin palmitic acid is present (C15H31COOH)
CH2 OCOC17H35
|
CH OCOC17H35
|
CH2 OCOC17H35
Tristearin (saturated)
In tristearin stearic acid is present (C17H35COOH)
CH2 OCOC17H33
|
CH OCOC17H33
|
CH2 OCOC17H33
Triolein (unsaturated)
In triolein oleic aicd is present (C17H33COOH)
CH2 OCOC17H29
|
CH OCOC17H29
|
CH2 OCOC17H29
Trilinolenin (unsaturated)
In trilinolenin linolenic acid in present (C17H29COOH)
If the fat contains different fatty acids then it is called mixed fat.
E.g. Dipalmito stearin (Two palmitic acid molecules and one stearic acid molecule)
CH2 OCO.C15H31
|
CH OCO.C15H31
|
CH2 OCO.C15H31
Dipalmito stearin
If two fatty acids only are present then it is called diglyceride.
If the acids are attached to first two carbon atoms the fat is called 1, 2 fat (or) , fat.
CH2 O COC15H31
|
CH O COC15H31
|
CH2 OH
Dipalmitin (1,2 palmitin)
If the acids are attached to 1 and 3 carbon atoms the fat is called 1,3 fat (or) , fat
 Biomolecules

CH2 O COC15H31
|
CH OH
|
CH2 O COC15H31
1, 3 palmitin
If only one acid molecule is attached to the carbon atom the fat is called monoglyceride. It is called 1-mono fat
(or) 2-mono fat depending on the carbons.
CH2 OCOC15H31
|
CH OH
|
CH2 OH
Monopalmitin (or) 1-palmitin
CH2 OH
|
CH OCOC15H31
|
CH2 OH
Monopalmitin (or) 2-palmitin
The fat may also contain one molecule each of oleic acid, palmitic acid and stearic acid.
The fat is called -oleo, -palmito, stearin.
CH2 OCOC17H33
|
CH OCOC15H31
|
CH2 OCOC17H35

In most unsaturated acids double bond is present at carbon-9. This is designated as 9.

Some acids contain more than one double bond which are not conjugated.

Lipids

Simple lipids (Homo lipids) Compound lipids (hetero lipids) Derived lipids

Fat and oils Waxes sperm Phospholipids Glycolipids

Triglycerides Whale wax (Phosphotids) (Cerebrosides)
Single (or) mixed Bees wax (Phosphoglycerides) Gangliosides
Triglycerides) Wool fat (Lecithin, Cephalin)
Spingomyelin

Steroids Terpenes Carotenoids

(Cholestrol, ergosterol)
 Biomolecules

Some important fatty acids present in fats.

No. of
Acid Formula Nature Fat
C-atoms
Butyric acid 4 CH3(CH2)2COOH Saturated Butter
Caproic acid 6 CH3(CH2)4COOH Saturated Butter oil
Caprylic acid 8 CH3(CH2)6COOH Saturated Coconut oil
Capric acid 10 CH3(CH2)8COOH Saturated Coconut oil
Palmitic acid 16 CH3(CH2)14COOH Saturated Animal fat
Stearic acid 18 CH3(CH2)16COOH Saturated Animal fat
Arachidic acid 20 CH3(CH2)18COOH Saturated Groundnut oil
Cerotic acid 26 CH3(CH2)24COOH Saturated Wool fat
Linoleic acid 18 CH3(CH2)4CH = CH2OH = Unsaturated Cotton seed oil
CH(CH2)7COOH
Oleic acid 18 CH3(CH2)7CH = CH(CH2)7COOH Unsaturated Animal fat
Chaulmoogric 18 CH = CH Unsaturated Chaurmoogri oil
acid CH(CH
| 2)12COOH

CH2 CH2

Waxes:
Waxes are insect secretions (or) protective coatings on animal furs and plant leaves.
Waxes are chemically esters of long chain saturated (or) unsaturated fatty acids with long chain monohydric
alcohols.
The fatty acids range between C14 & C36
The alcohols range between C16 & C36.
Free fatty acids, alcohols and some hydrocarbons are also present mixed with the ethers.
Waxes have higher melting points than neutral fats.
Examples :
1) Bees wax :- Secreted by bees. It is a palmitic acid ester of myricyl alcohol. (C30 H61 OH)
2) Spermaceti:- Palmitic acid ester of cetyl alcohol (C16H33OH). It is obtained from sperm whale oil.
3) Lanoline wool (or) fat : Palmitic acid (or) Stearic acid (or) oleic acid ester of cholesterol. It is obtained from
wool.
Compound lipids:
Compound (or) Heterolipids contain additional groups such as phosphoric acid, nitrogen containing bases and
other substituents.
Compound lipids are classified into
1) phospholipids 2) Glycolipids 3) Terpenes.
 Biomolecules

Phospholipids
Phospholipids contain phosphoric acid, nitrogen containing bases and other substituents as additional groups.

CH2 O fatty acid CH2COOR

CH O fatty acid (or) CHCOOR'

O
CH2 O P Base
CH2 O P OR"
P = phosphoric acid
O
Phospho lipid

The common examples of phospholipids are Lecithins and Cephalins which are found principally in the brain,
nerve cells, and liver of Animals.
Phospholipids are also found in egg yolks, yeast, soyabeans & other foods.
Phospholipids are also used as detergents to emulsify fat for transport within the body.
Phospholipids are further classified into
1) Glycerophosphatides
2) Phosphoinositides
3) Phosphosphingosides.
Glycerophosphatides contain glycerol, Fatty acids, phosphoric acid and a base. The base may be choline,
ethanolamine, serine (amino acid).
In phosphoinositides the cyclic hexahydric alcohol (inositol) replaces the base.
In phosphosphringosides glycerol is replaced by complex amino alcohol (sphingol).
Glycolipids esters of fatty acids with carbohydrates and may contain nitrogen but no phosphorous.
Structure of some phospholipids
CH2OCOC15H31

CHOCOC15H31
O

CH2O P O CH2CH2N+(CH3)3

OH
Lecithin
 Biomolecules

CH2OCOC15H31

CHOCOC15H31
O

CH2O P CH2CH2NH3+

OH
Cephalin

Derived fats:-
Terpenes are polymers of 5-carbon unit called Isoprene. The side chains of A, E and K and the carotenes belong
to this group.
Derived fats are hydrolysis products of simple and compound lipids. The products include Glycerol, fatty acids,
sphingosine (amino alcohol), steroids, terpens & Carotenoids.
Sterol means solid Alcohol.
Cholestrol, ergosterol, bile acids, sex harmons, Dvitamin are the some of sterol derivatives.
Sours of cholestrol are solid alcohol from bile, brain, nervous tissues, adrenal glands and egg yolk.
Formula of cholestrol is C27 H45 OH.
Ergosterol:- Solid alcohol present in fungi, yeast and ergot.
Formula of Ergosterol is C28 H43OH.
Biological importance of lipids:-
Fats are important food reserves of animals and plant cells.
Simple lipids acts as important sources of energy in our food supply.
Phospholipids serve as structural materials of cells and tissues such as cell membrane.
Phospholipids are used as detergents to emulsify fat for transport within the body.
Cholestrol is the principal sterol of higher animals and abundant in nerve tissues and gallstones.
Simple lipids can acts as heat insulators and shock absorbers for the living organism.
Lipids are essential for the absorption or fat soluble vitamin like A, D, E & K.
Enzyme activators.
 Hormones

Hormones are molecules of carbon compounds that transfer biological information from one group of cells to
distant tissue (or) organs.
Hormones are produced in ductless glands and they are called endocrine glands.
Hormones are also called chemical messengers because of the action of hormones as communication
among cells.
Hormones are required in trace amounts but are highly specific in their functions.
Deficiency of any hormone leads to particular disease.
Hormones are continuously produce but not stored in the body.
Hormones are of Animal (or human) origin and plant origin.
Hormones are carried to different parts of the body by the blood stream where they control the various body
functions.
Plant hormones are called growth hormones.
The term hormone was first introduced by Baylers and Starling in 1902 for secretion produced by intestinal
mucosa.
The site of action of hormone is away from their origin.
Hormones are generally proteins but not all of them are proteins.
Hormones not only control different aspects of metabolism but also perform many other functions such as cell
and tissue growth, heart rate, blood pressure, kidney function, secretion of digestive enzymes, the
reproductive system etc.
In mammals the secretion of hormones is controlled by the anterior lobe of the pituitary gland present at the
base of the brain. Classification of Hormones
Based on the structures of hormones these are classified into three main types.
1) Steroid hormones 2) Protein hormones
3) Amine hormones.
Steroid hormones are mostly secreted by testis, adrenal cortex of males and ovary.
The common examples of steroid hormones are testosterone, dihydrotestosterone, and androgens.
During puberty these stimulate the male sex characteristics.
In females estrogens are female sex hormones which are produced in ovaries and are responsible for
development of female sex characteristics during puberty.
Protein hormones are produced by pancreas, parathyroid, pituitary and gastro intestinal mucosa.
The common examples of protein hormones are oxytoxin, vasopressin and Insulin.
Amino hormones are produced by thyroid and adrenal medulla.
Steroid hormones contain a steroid nucleus which is based on a four ring network consisting of three
cyclohexane rings and one cyclopentane ring.
 Biomolecules

CH3 OH

CH3 H

H H
HO
O
Steroid nucleus Testosterone

OH CH3 COCH3
CH3

H CH3 H

H H H H
HO O
Estradiol Progesterone

Functions of Hormones
I. Steroid hormones
Steroid hormones are two types.
1) Adrenal cortical hormones (cartico steroids
2) Sex hormones.
Cartico steroids are mainly two types.
1) Mineralo corticoids 2) Gluco corticoids.
Mineralo corticoids are produced by different cells in the adrenal cortex.
Mineralo corticoids useful for watersalt balance in the body. These cause excretion of potassium in urine.
Glucocorticoids are made by cortex. These are useful to modify certain metabolic reactions.
Gluco corticoids have antiinflammatory effect.
Sex hormones are three types. 1) Male sex hormones (or) androgens 2) Female sex hormones (or)
estrogens 3) pregnancy hormones (or) progenstines.
Testosterone is the major male sex hormone produced by testes and responsible for the development of male
secondary sexual characteristics such as deep voice, facial hair, sturdy physical structure.
Synthetic testosterone analogs are used in medicine to promote muscle and tissue growth. These are also
used by atheletes illegally to promote their muscle and tissue growth.
Estradial is the main female sex hormone responsible for development of secondary female characteristics
such as breast development, shrill voice, and long hair and participates in control of the menstrual cycle.
Progesterone is responsible for preparing the uterus for implantation of the fertilized egg. These are also
useful as birth control agents.
Non steroid hormones :
Non-steroid hormones are mainly two types.
1) Peptide hormones
2) Amino acid derivative hormones.
Peptide hormones are peptide compounds.
 Biomolecules

Ex. Insulin, oxytocin.

Insulin is responsible for controlling the glucose level in our blood and its deficiency leads to the disease
diabetes.
Insulin is secreted by pancreas.
Insulin is a dipeptide consisting of two peptide chains bound by three S-S bonds. One chain contained 21
amino acids and the other chain contained 30 amino acids.
Sulphur bridges connect cysteine amino acids in the two chains.
Oxytocin is produced by the pituitary gland.
Oxytocin induces lactation in breasts and helps in the contraction of uterus after child birth.
Amine hormones are amino acids and organic amine compounds.
Ex. Thyroxine, Adrenaline, & nor adrenaline.
Thyraxine is secreted by thyroid gland and it is responsible for the control of metabolism of some proteins,
lipids and carbohydrates
Deficiency of thyroxine leads to the disease goitre.
Addition of KI to table salt do not lead to the thyroxine deficiency.
Adrenaline is responsible for maintenance of pulse rate and blood pressure.
Non Adrenaline is secreted by adrenal glands and secretion of excess of non adrenaline in our body, when we
are in anger causes hypertensions.
Amino acid derivatives:
Amino acid derivatives are thyroidal hormones.
e.g.: Thyroxin, Tri iodo thyronine
Thyroidal hormones effect the general metabolism regardless of the specific activity. For this reason thyroid
gland is called pace setter of the endocrine systems.
Site of Activity :
On the basis of site of activity hormones are divided into two categories.
The first category effects the properties of plasma membrane.
Ex. All peptide hormones (Insulin, hormones of pituitary gland).
The hormones of other category are taken into the cell and carried to the cell nucleus and influence the gene
expression.
Plant hormones :
Plant hormones regulate growth and physiological function at a site remote from the place of secretion.
Plant hormones are produced by higher plants.
The plant hormones are
1) Auxins 2) Gibberlins
3) Cytokinins 4) Ethylene
5) Traumatic acid 6) Abscicic and
7) Morphactin.
Auxins are cyclic carbon compounds and pentene derivatives.
 Biomolecules

Auxine promote growth along the longitudinal axis.

Gibberlinus are the derivatives of cyclic compound gibbane.
Gibberlinus cause bolting (shoot elongations) and flowering.
Cytokinins stimulate cell division, promote cell elongation and induces flowering in short day plants.
Ethylene accelerates the colouring of harvested fruits like lemons, induces rooting and flowering.
Transmatic acid is an open chain dicarboxylic acid with one double bond and induces cell division.
Absicic acid is a sesquiterpene and induces prototropism.
Morphactin inhibits mitosis, formation of branches is promoted. These are derivatives of fluorine-9- carboxylic
acid.
General Biological functions of animal hormones :
Maintaining constant internal environment of organs.
Ex. Insulin maintains constant sugar level in blood.
Sex hormones develops secondary sexual characters.
Adrenaline is responsible for some emergency reaction.
Some metamolic reaction are controlled by hormones.