SG Chemistry Classes
Biomolecules
There are 5 types of biomolecules
i) Carbohydrates ii) Protein iii) Fats iv) Vitamins v) Nucleic acid
Carbohydrate
3 types
i) Monosaccharides ii) Oligosaccharides iii) Polysaccharides
Monosaccharides
General - Cx(H2O)y
x=6 y=6
C6(H2O)6 = C6H12O6
Ex - Glucose, Fructose, Galactose ,Ribose.
Exception -Rhamnose C6H12O5
Rhamnose is a monosaccharide but doesn’t satisfy the general formula Though acetic acid
satisfies the common formula it is not a carbohydrate.
x = 2 y = 2 C2H4O2
CH3 COOH (acetic acid)
Glucose (C6H12O6) and Fructose (C6H12O6)
Anomer - The position of OH group at C-1 carbon defines the alpha-glucose and beta-
glucose . Isomer which differs in the configuration of OH group at C-1 position are called
anomer that is alpha-glucose and beta-glucose.
Chemical properties of Glucose
Reaction with Bromine water
Aldehyde on oxidation with bromine water produces Gluconic acid.
Reaction with HI
On strong reduction of glucose in the presence of HI produces Hexane.
The above reaction shows that the carbon atoms in glucose are linked in straight chain.
Nucleophilic Addition reaction
Glucose does not undergo the following reaction:
Oligosaccharids
2 - 10 monosaccharides
Disaccharides (2 Monosaccharides)
Sucrose = Glucose + Fructose
Lactose = Galactose + Glucose
Maltose = Glucose + Glucose
Fructose = Fruit Sugar Sucrose = Cane sugar Maltose = Grape sugar
Lactose = Milk sugar
Invert sugar - Sucrose is made up of D(+)glucose and D(-)fructose one of its component is in
inverted form. So Sucrose is known as invert sugar.
Polysaccharides
It is a chain of large no. of monosaccharides Ex: Starch, Cellulose, Glycogen
It is also known as non-sugar because it does not taste sweet.
Monosaccharides are attached with each other through Glycosidic bond.
Cellulose - it is made up of glucose, plant cell wall is made up of cellulose.
Glycogen - It is also known as animal starch. It is also made up of glucose.
Starch - Starch is a polymer of glucose. It is used to store food in plant. Starch is made up
of two sub units Amylose and Amylopectin.
(i) Amylose – Straight chain - Water soluble
(ii) Amylopectin - Branched chain - Water insoluble
Starch Glycogen
Alpha D-glucose Alpha D-glucose
Amylose(Straight Chain) + Branched chain
Amylopectin(Branched chain)
Used for food storage in Plants. Used for food storage in Animals.
Carbohydrates can also be classified as i) Reducing Sugar ii) Non reducing Sugar
Reducing Sugar :
In reducing sugar the aldehyde and ketone group are free Example - All monosaccharide,
Maltose & Lactose
(Disaccharide)
Non-Reducing Sugar
The sugar of which aldehyde and ketone group are not free i.e. the reducing group is bonded
is known as non-reducing sugar.
Example : Sucrose
Vitamin
The organic compounds which are required in the diet in small amount for normal maintenance or
optimum growth and health of body.
2 Types :
Fat soluble ——> (water insoluble) ——> Can be stored ——> Vit A, D, E, K
Fat insoluble ——> (water soluble) ——> Can’t be stored ——> Vit B, C
Except - Vit B12 - Though it is fat insoluble, it can be stored in body.
E. Coli bacteria helps Vit B12 to get stored.
Vitamin Deficiency
A Xeropthalmia , Night blindness
B1 Beri Beri
B2 Cheilosis
B6 Convulsions
B12 Pernicious Anaemia
C Scurvy
D Rickets and Osteomalacia
E Fragility of RBC and Muscle weakness
K Delay in Blood clotting
Protein -
It is made up of amino acids.
H+
R O R
R
H 2N C C O H H3+N C COO-
H2N C COOH
H H
H
Zwitterionic form
R O R O R O R O
HN C C HN C C HN C C ————>
HN C C
n
H H H H
Polymer of Amino acid is known as Protein.
N.B- Both +ve and –ve - zwitterionic
Both acid and base - Amphoteric
Amino acid acts as amphoteric substances due to presence of both basic (NH2) and acidic (-
COOH) group in it.
Amino acids can be classified into two types
i) Essential Amino Acid ii) Non Essential Amino acid
Essential Amino Acid- The Amino acid which can’t be formed in our body and we need to consume
from Nutrition is known as Essential Amino Acid.There are 9 Essential Amino Acid.
Non Essential Amino acid- The Amino acid which can be formed in our body and we don’t need to
consume from Nutrition is known as Non Essential Amino Acid.There are 11 Non Essential Amino
Acid.
Biocatalyst or Enzyme - Those are the proteins which can catalyse a biochemical reaction in our
body.
Proteins are arranged in the form of helical structure known as alpha-helix. In between alpha
helix hydrogen bond is present between NH2 and COOH group which gives rise to helical
structure and stabilises the protein.
Protein can remain in the form of alpha or primary or 10 helix.
They coiled further to form 20, 30 helix.
When we apply heat energy or change the pH , due to breakage of hydrogen bond between
them.This is known as protein denaturation.
Ex-Boiling of egg, Cuddling of milk
On the basis Structure, Protein can be classified into two types
i) Globular Protein ii) Fibrous Protein
GLOBULAR PROTEINS
• When the chains of polypeptide, coil around to give spherical structure it is called as globular
protein.
• Ex-Albumin, Insulin
• Globular proteins are soluble in water.
FIBROUS PROTEIN
• When polypeptide chain are parallaly arranged and held together by hydrogen and disulphide
bond it is known as fibrous protein.
• Ex- Myosin, Keratin
Fibrous protein are water insoluble.
Polypeptide - When more than to amino acid are joined together by peptide bond is known as
polypeptide.
Nucleic Acid
DNA = Deoxyribonucleic acid - 4 Oxygen
RNA = Ribonucleic acid -5 Oxygen
Pentose Sugar + Nitrogenous Base
Nucleoside + Phosphate group
Nucleotide + Nucleotide + Nucleotide
= Nucleic Acid
Pentose Sugar -
DNA - Deoxyribose Sugar RNA - Ribose Sugar
Nitrogenous base -
Purine Pyrimidine
Adenine Cytosine
Guanine Thiamine , Uracil
RNA consist of uracil in place of Thiamine.
Adenine makes double hydrogen bond with Thiamine and uracil and vice versa. A=T
Guanine makes triple hydrogen bond with cytosine and vice versa. G=C
Polymer of Nucleotide is known as Nucleic Acid.
RNA is of 3 types-
mRNA –messenger RNA
rRNA- ribosomal RNA
tRNA- transfer RNA
• Two DNA strand run anti parallel to each other i.e. one is 5’ to 3’ another is from 3’ to 5’.
Fat
Fat is composed of fatty acid and Glycerol.
Glycerol
Trihydroxy propane
Fatty acid
Long chain of carboxylic acid
Arachdnoic acid
In fats fatty acid are esterified with glycerol
HORMONES
Hormones are molecules that are produced by endocrine glands which are transported by blood.
Glucagon increases the blood glucose level ;insulin decreases the blood glucose level.
