BIOMOLECULE

SHORT NOTES

Carbohydrates: They are optically active polyhydroxy aldehyde or ketone which produces on hydrolysis.
Classification of Carbohydrates
Monosaccharide Oligosaccharides Polysaccharides
• These are carbohydrates which • These are carbohydrates which  These are carbohydrates which
cannot be hydrolyzed into give two to ten monosaccharide give a large number of
simpler units. units on hydrolysis. monosaccharide units on
Eg. glucose, fructose, ribose, • They are further classified as hydrolysis.
galactose etc disaccharides, trisaccharides, Eg. starch, cellulose, glycogen
tetrasaccharides etc. etc.
Eg. Sucrose, maltose, lactose etc.
Glucose: It occurs freely in nature as well as combined  Cell wall of bacteria and plants is made up of
form. Present in sweet fruits. cellulose
Structure of glucose  Carbohydrates are used as raw materials for
 Glucose is an aldohexose and is known as many important industries like textiles, paper,
dextrose lacquers and breweries
 Molecular formula-C6H12O6
 All the six carbon atoms are linked in a straight
chain Amino Acids
Cyclic structure of glucose  These are compounds containing amino (–
NH2) and carboxyl (–COOH) groups.
 classified as α, β, γ, δ
 Simplest amino acid is glycine (H2N-CH2-
COOH).
 All other naturally occurring α-amino acids are
optically active, since the α-carbon atom is
asymmetric.
Anomeric carbon: differ only in the configuration of
hydroxy group.
Inversion of cane sugar
Cane sugar is sucrose, which on hydrolysis gives an
equimolar mixture of D(+)glucose and D(-)fructose.
C12H22O11 + H2O → C6H12O6 + C6H12O6
Peptide linkage
Glycosidic linkage: During the formation of a
When two molecules of amino acids combine, the
disaccharide or polysaccharide, the monosaccharides
amino group of one molecule reacts with –COOH
are joined together through oxide linkage by losing
group of another molecule by losing one water
water molecules.
molecule to form a CO-NH linkage, commonly called
Uses of carbohydrates
peptide linkage.
 storage molecules as starch in plants and
glycogen in animals
Structure of proteins
Fibrous protein: fibre like structure and insoluble in water
Globular structure: chains of polypeptides coil around to give a spherical shape
Primary structure Secondary structure Tertiary structure Quaternary structure 1
It gives the sequence of The secondary structure of The tertiary structure Proteins contain two or
amino acid molecules in a protein refers to the shape represents overall folding more polypeptide chains
polypeptide chain of in which a long of the polypeptide chains called sub-units.The spatial
protein. Any change in the polypeptide chain can arrangement of these sub-
Prepared by Krishna Sampreeth | WOVHSS,MUTTIL
 BIOMOLECULE
SHORT NOTES

primary structure creates a exist. units is known as

different protein. quaternary structure.
Denaturation of protein
When a protein is subjected to physical change (like change in temperature) or chemical change (like change in pH),
it loses the biological activities. This process is called denaturation of protein. During denaturation, secondary and
tertiary structures are destroyed, while primary structure remains unaffected.
E.g. coagulation egg white on boiling, curding of milk etc.
Vitamins: Vitamins are nutrients your body needs to develop and function properly.
Classification of vitamins
Fat soluble-ADEK
Water soluble-BC
Vitamin Source Deficiency diseases
1. Vitamin A  Fish liver oil • Night blindness
 Carrot • Xerophtalmia
 Butter
 Milk
2. Vitamin B1(Thaimine)  Yeast • Beriberi
 Milk • Retarded growth
 Green vegetables
 Cereals
3. Vitamin B2(Ribofalvin)  Milk • Digestive disorder
 Egg white
 Liver
 Kidney
4. Vitamin B6(pyridoxine)  Yeast • Convulsions
 Milk
 Egg yolk
 Grams
5. Vitamin B12  Meat • Pernicious anemia(RBC
 Fish deficient in Hemoglobin)
 Egg
 Curd
6. Vitamin C(Ascorbic acid)  Citrus fruit • Scurvy(bleeding gums)
 Amala
 Green leaf vegetables
7. Vitamin D  Sunlight • Rickets
 Fish
 Egg yolk
8. Vitamin E  Vegetable oils • Muscular weakness
 Sun flower oil
9. Vitamin K  Green leafy vegetables • Increase blood clotting time

DNA RNA
• Carries genetic information • It put genetic information to work in the cell
• Sugar is deoxyribose • Sugar is ribose 2
• Double stranded • Single stranded
• Occurs in cell nucleus • Occurs in cytoplasm
• Undergoes replication • Dose not undergo replication
• Thymine adenine and guanine are present • Cytosine adenine and guanine are present
Prepared by Krishna Sampreeth | WOVHSS,MUTTIL