Introduction
All the organic compounds/molecules that can be obtained
from a living cell/tissue/organism.
There is a wide diversity of living organisms in our biosphere
(part of the Earth’s surface and atmosphere in which plants
and animals can live).
How To Analyse Chemical Composition?
How To Analyse Chemical Composition?
Two components are formed
Filtrate Retentate
Acid soluble Pool Acid insoluble Pool
Micromolecules Macromolecules
(Mol. Weight (Mol. Weight
< 1000 daltons) > 1000 daltons)
e.g. Amino acids, e.g. Protein, Nucleic Acid,
N- base, Monosaccharides Polysaccharide
Analysis of Inorganic Elements & Compounds
Analysis of Inorganic Elements & Compounds
Take a small amount of a living tissue.
(e.g. Leaf or liver)
Wet weight is recorded
Dry it-all water evaporates
The tissue is fully burnt
Carbon compounds are oxidised to
gaseous form like CO2, water vapour
The remnant is called 'Ash'.
Ash contains many inorganic elements like
calcium, magnesium, etc. & inorganic
compounds like sulphates, phosphates etc
Priority order of organic compounds present in protoplasm:
(1) Water > Protein > Carbohydrate > Lipid
(2) Lipid > Protein > Carbohydrate > water
(3) Protein > Carbohydrate > Lipid > Water
(4) Protein > Water > Lipid > Carbohydrate
Ans. 1
Carbohydrates
Carbohydrates are the main source of energy, i.e. these
are the main respiratory substrates.
Based on the number of saccharide units obtained upon
hydrolysis, carbohydrates are classified as:
Carbohydrates
Based on hydrolysis
Monosaccharides Oligosaccharides Polysaccharides
Carbohydrates
Carbohydrates
Monosaccharides Oligosaccharides Polysaccharides
o Trioses (2-10 units of
monosaccharides)
o Tetroses o Homopolysaccharides o Heteropolysaccharides
o Pentoses o Disaccharides Cellulose Chondroitin
o Hexoses Maltose Starch Hyaluronic acid
Lactose Glycogen Heparin
o Heptoses
Sucrose Chitin Pectin
Inulin Hemicellulose
Dextrin
Glycosidic Bond Formation
6 6
CH2OH CH2OH
H C5 O H C5 O H
H
C4 H 1 H 1
OH C C4 OH C
H H
HO C3 2
C OH HO C3 2
C OH
H OH H OH
Glucose Glucose
Glycosidic Bond Formation
HO
H2O
6 6
CH2OH CH2OH
H C5 O H C5 O H
H
C4 H 1 H 1
OH C C4 C
H OH H
HO C3 2
C OHO HO C3 2
C OH
H OH H OH
Glucose Maltose Glucose
-1-4 glycosidic linkage
A dehydration reaction links two glucose molecules to produce
maltose. If the formula for glucose is C6H12O6, then what is the
formula for maltose?
(1) C12H24O12
(2) C12H22O11
(3) C12H24O11
(4) C12H20O10
Ans. 2
Polysaccharides / Glycans
Polysaccharides are composed of a large number of
monosaccharide units
Left end Right end
Non-reducing end Reducing end
CH2OH CH2OH CH2OH CH2OH CH2OH
O H O H O H O H O
H H H H H H
H H H H H
OH H OH H OH H OH H OH H
O O O O O
HO
H OH H OH H OH H OH H OH
Glucose unit Glucose unit Glucose unit Glucose unit Glucose unit
Polysaccharides / Glycans
Cellulose
The unbranched, linear polymer of β-D-Glucose units
(6000 - 10,000) with β – 1’- 4” glycosidic linkage.
Cells Walls
Cells
Cellulose
chains
Glucose
molecules
Plant
Cellulose does not form blue colour with Iodine because
(1) It is a helical molecule.
(2) It does not contain complex helices and hence cannot
hold iodine molecules.
(3) It breaks down when iodine reacts with it.
(4) It is a disaccharide.
Ans. 2
Polysaccharides / Glycans
Starch
The main stored food in plants.
It is a polymer of a α–D-Glucose units.
Starch gives a blue color with an iodine solution.
Starch present in potatoes contains:-
20% amylose 80% amylopectin
Polysaccharides / Glycans
Glycogen
A storage form of carbohydrate in animals
The storage region of glycogen is liver and muscles
Polysaccharides / Glycans
Chitin
Linear polymer of β-N-acetyl D-Glucosamine.
Chitin is an important component of the exoskeletons of
Arthropods and fungal cell walls.
Inulin
Linear polymer of 25-35 fructose units linked by β–1’–2”
glycosidic bonds.
Hey,
Inulin and Insulin
both are different
terms.
In the above diagrammatic representation of glycogen, glycosidic
bonds represented by A,B and C are:
A B C
(1) α–1'–4'' α–1'–6'' α–1'–4''
(2) β–1'–4'' β–1'–6'' β–1'–4''
(3) α–1'–6'' α–1'–4'' α–1'–4''
(4) β–1'–6'' α–1'–4'' β–1'–4''
Ans. 3
Lipids
Fats and their derivatives are combinedly known as lipids.
Lipids
Simple lipid or Conjugated or Derived
Neutral Fats Compound Lipids Lipids
Lipids
Fatty Acids
A fatty acid has a carboxyl group attached to an R group.
The R group could be a methyl (–CH3), ethyl (–C2H5) or a
higher number of –CH2 groups (1 carbon to 19 carbons).
H H H H H H H
O
C C C C C C C C H
HO H H H H H H H
Carboxylic Hydrocarbon chain
Acid group FATTY ACID
Lipids
Fatty Acids
Simple Lipids Contain Two Types Of Fatty Acids
S. No. Saturated Fatty Acids Unsaturated Fatty Acids
Only single bonds
1 are present between
C-C atoms.
H H H H H H H
O
C C C C C C C C H
HO H H H H H H H
Saturated fatty acid
Lipids
Fatty Acids
Simple Lipids Contain Two Types Of Fatty Acids
S. No. Saturated Fatty Acids Unsaturated Fatty Acids
Only single bonds Double bonds are also
1 are present between present along with
C-C atoms. single bonds between
C-C atoms.
H H H H H H H
O
C C C C C C C C
HO H H H H H H H
Unsaturated fatty acid
Lipids
Simple Lipids Contain Two Types Of Fatty Acids
S. Saturated Fatty Unsaturated Fatty
No. Acids Acids
2 Also known as non- Also known as essential
essential fatty acids, fatty acids because they
because they can be can't be synthesised in
synthesized in animal animal body. So, it is
body. So, it is not essential to take them
essential to take them with food.
with food.
Lipids
Simple Lipids Contain Two Types Of Fatty Acids
S. Saturated Fatty Unsaturated Fatty
No. Acids Acids
3 Lipids with more Lipids with more amount
amount of saturated of unsaturated fatty acids
fatty acids are mostly are mostly present in
present in solid form liquid form at normal
at normal temperature.
temperature. e.g. Coconut oil,
e.g. Butter, Ghee Mustard oil.
Lipids Simple Lipids Contain Two Types Of Fatty Acids
S. Saturated Fatty Unsaturated Fatty
No. Acids Acids
4 Metabolically less Metabolically more
reactive. So, the reactive.
tendency to get stored So, the tendency to get
in the body is high. stored in the body is low.
Lipids Simple Lipids Contain Two Types Of Fatty Acids
S. Saturated Fatty Unsaturated Fatty
No. Acids Acids
5 Mostly animal fat Mostly plant fat
contains high contains high
amount of SFA amount of USFA
➢ Palmitic acid = Arachidonic acid (20C)
16C (C16H32O2)
CH3—(CH2)14—COOH
Lipids
Glycerol
Another simple lipid is glycerol.
Glycerol is a trihydroxy alcohol. It is also called trihydroxy
propane.
Esters of fatty acids & glycerol are called glycerides.
CH2—OH
CH—OH
CH2—OH
Glycerol
(Trihydroxy propane)
Lipids
Formation of Glyceride
Given molecular formula belongs to which of the following
groups of biomolecules?
O
(1) Carbohydrates
O CH2—O—C—R1
(2) Proteins
R2—C—O—CH O
(3) Nucleic acids
CH2—O—C—R3
(4) Triglycerides
Ans. 4
A typical fat molecule is made up of:
(1) Three glycerol molecules and one fatty acid molecule
(2) One glycerol and three fatty acid molecules
(3) One glycerol and one fatty acid molecule
(4) Three glycerol and three fatty acid molecules
Ans. 2
Identify the given structure
CH2—OH
CH—OH
CH2—OH
(1) Glycine (2) Glycerol
(3) Valine (4) Serine
Ans. 2
Lipids
Phospholipids
O
Fatty chain 1
O CH 2—O—C—R 1
R 2—C—O—CH O Phosphate
Fatty chain 2
CH 2—O—P—O—CH 2—CH 2
Glycerol OH N
CH3 CH3
CH3
Phospholipid Nitrogenous
(Lecithin) Compound
Lipids
Derived Lipids
Lipids derived from simple or conjugated lipids are
called as derived lipids.
Some tissues, especially the neural tissues, have lipids
with more complex structures.
Cholesterol
HO
Identify the following molecule.
HO
(1) Phospholipid (2) Lecithin
(3) Cholesterol (4) Oleic acid
Ans. 3
Proteins
Generalised Structure of Amino Acid
H H O
H N C C OH
Amino Carboxylic
Group R acid group
Variable -carbon
Alkaline Side Chain Acidic
Proteins
Generalised Structure of Protein Amino Acids
Amino acids are substituted methanes.
H
H2 H
N C H
COOH
H
R
Variable
Side Chain
Proteins
Structures of Amino Acids
Based on the nature of R group there are many types of amino
acids.
COOH COOH COOH
H—C—NH2 H—C—NH2 H—C—NH2
H CH3 CH2—OH
Glycine Alanine Serine
Amino Acid
The given structural formula represent amino acids (labelled by
as X, Y and Z)
COOH COOH COOH
H—C—NH2 H—C—NH2 H—C—NH2
H CH3 CH2—OH
X Y Z
Identify the correct name of X, Y and Z.
(1) Alanine, serine and glycine respectively
(2) Tyrosine, cysteine and glutamic acid respectively
(3) Glycine, alanine and serine acid respectively
(4) Cysteine, glutamic acid and tyrosine respectively
Ans. 3
