Important Biomolecules for cells 101.pdf

Biomolecules are chemical compounds that are vital components of living organisms, playing key roles in biological processes. These molecules include carbohydrates, lipids, proteins, nucleic acids, and other substances that contribute to the structure, function, and regulation of cells and organs. Each type of biomolecule has a unique structure and specialized functions, ranging from energy storage to the transmission of genetic information.

1. BIOMOLECULES-CLASS XI BIOLOGYBIOMOLECULES-CLASS XI BIOLOGY 11
BIOMOLECULESBIOMOLECULES
PREPARED BY
S RATH PGT BIO
K V III BBSR
http://students-learn.blogspot.com/

2. BIOMOLECULES-CLASS XI BIOLOGY 2
Biomolecules of cells
All carbon compounds that are found in
the living tissues are called Biomolecules.
Example-carbohydrate, fat, protein, amino
acids, lipids etc.

3. BIOMOLECULES-CLASS XI BIOLOGY 3
Classification of
Biomolecules
BIOMOLECULES
MICROMOLECULES
Mol. Wt.< 1000
MACROMOLECULES
Mol. Wt. >1000
Amino acid nucleotides
Sugars , lipids
Polysaccharides, proteins
Nucleic acids

4. BIOMOLECULES-CLASS XI BIOLOGY 4
Amino acids
These are organic compounds which
contain an amino group and an acidic
group .
They are substituted methane with 4
substituent groups occupying the 4
valency positions of the carbon; these
are hydrogen, carboxyl group, amino
group & a variable group designated as
R group.

5. BIOMOLECULES-CLASS XI BIOLOGY 5
Amino acids
There are 20 amino acids occur in protein.
A specific characteristic property of amino
acids is the ionizable nature of amino and
carboxyl group, so the structure of amino
acids changes in solutions of different pHs.

6. BIOMOLECULES-CLASS XI BIOLOGY 6
Types of amino acids
Basic – lysine arginine
Acidic – glutamic acid aspartic acid
Neutral – alanine glycine valine
Aromatic – phenyl alanine , tyrosine,
tryptophan

7. BIOMOLECULES-CLASS XI BIOLOGY 7
Sugars
Simplest sugars are monosaccharides,
which cannot be hydrolysed further
composed of 3-7 carbon atoms. E.g.
glyceraldehydes, ribose, glucose,
fructose etc.
They have either free aldehyde or
ketone group which reduce cupric ion to
cuprous ion ,called reducing sugar.

8. BIOMOLECULES-CLASS XI BIOLOGY 8
Sugars
Oligosaccharides may have two or a few
monosaccharides.
Bond between two monosaccharides is
called glycosidic bond.

9. BIOMOLECULES-CLASS XI BIOLOGY 9
lipids
lipids
Straight chain
compound
Fused hydrocarbon
Ring e.g. cholesterol
simple compound
oil phospholipids
fats
waxes
glycolipids
sphingolipids

10. BIOMOLECULES-CLASS XI BIOLOGY 10
Nucleotides
Organic compounds with heterocyclic rings.
A nucleotide consists of a nitrogenous base, a
pentose sugar and a phosphate group.
A nucleoside has a nitrogenous base attached to
a pentose sugar.
The nitrogenous bases are called adenine,
guanine, thymine, cytosine and uracil
Polymerised nucleotides form DNA and RNA
which are the genetic material.

11. BIOMOLECULES-CLASS XI BIOLOGY 11
Primary and secondary
metabolites
Metabolites may be primary or secondary type.
Primary metabolites have identifiable functions
and play specific roles in the normal physiological
processes. E.g. amino acids, nitrogenous bases,
nucleic acids etc.
Secondary metabolites are products of certain
metabolic pathways. E.g. pigments, rubber, gums,
resins, carotenoids etc.

12. BIOMOLECULES-CLASS XI BIOLOGY 12
Polysaccharides
These are a class of organic compounds
(carbohydrates) which are long chain polymers
of monosaccharides.
They are of two types: homopolysaccharides,
heteropolysaccharides
Homopolysaccharides- cellulose, starch, inulin
Heteropolysaccharides- chitin

13. BIOMOLECULES-CLASS XI BIOLOGY 13
Proteins
They are heteropolymers containing a string or
strings of amino acids.
A peptide bond formed between the carboxyl
group and the amino group of successive amino
acids, joins the amino acids together.
Proteins result from the 20 amino acids ,
depending on the no.of amino acids and
sequence of amino acids.
There are 4 levels of protein structure.

14. BIOMOLECULES-CLASS XI BIOLOGY 14
Primary structure of protein
Protein exists as a long chain of amino acids
arranged in a particular sequence.
It is nonfunctional.
Position of amino acid in a protein is obtain
from this.
1
st
a. a is called N-terminal and last is called C-
terminal a. a.

15. BIOMOLECULES-CLASS XI BIOLOGY 15
Secondary structure of
protein
There is interaction between every fourth a. a
by formation of hydrogen bond. The
polypeptide has a helical shape. E.g. keratin.
Only right handed helix are formed.
If two or more chains are held together by
intermolecular hydrogen bonds, the structure
is called pleated sheet. E.g. silk fibres.

16. BIOMOLECULES-CLASS XI BIOLOGY 16
Tertiary structure of
protein
When a polypeptide chain becomes further
stabilised by folding and coiling by the
formation of ionic or hydrophobic bonds or
disulphide bridges, the protein is said to be
tertiary structure.
E.g. amylase, pepsin and other enzymes.

17. BIOMOLECULES-CLASS XI BIOLOGY 17
Quaternary structure of
protein
When a protein has many sub units, each
having primary, sec. And tertiary st. of its own,
the protein is said to be quaternary.
E.g. haemoglobin, insulin

18. BIOMOLECULES-CLASS XI BIOLOGY 18
Enzymes
They are proteins that catalyse biochemical
reaction, so called biocatalysts.
Specific for their substrate.
Each enzyme require a specific (optimum) pH &
temp.
Accelerate a reaction by reducing the activation
energy.

19. BIOMOLECULES-CLASS XI BIOLOGY 19
Nomenclature of enzyme
Named by adding the suffix ‘ase’ to the substrate.
E.g. sucrase
According to the physiological activity it
catalyses. E.g. oxidase, dehydrogenase
The source from which they are obtained.
E.g.papain from papaya.

20. BIOMOLECULES-CLASS XI BIOLOGY 20
Classification of enzyme
Oxidoreductase
Transferase
Hydrolases
Lyases
Isomerasees
ligases

21. BIOMOLECULES-CLASS XI BIOLOGY 21
Mechanism of enzyme
action
Three dimensional structure of enzyme has one
or more active site where the substrate binds.
Active site acts as ‘ lock’ into which substrate fits
in like a ‘key’.
The point where substrate binds is called
‘substrate binding site’.
Substrate binding causes lowering of activation
energy & reaction to proceed at a faster rate.
Binding of substrate induces the enzyme to alter
its shape and fit more tightly.
Breaking of chemical bond of substrate and
formation of E-P complex.
Enzyme releases product and free enzyme take
up another molecule.

22. BIOMOLECULES-CLASS XI BIOLOGY 22Activation energy requirement

23. BIOMOLECULES-CLASS XI BIOLOGY 23
Factors affecting enzyme
action
Temperature
pH
Substrate concentration
chemicals

24. BIOMOLECULES-CLASS XI BIOLOGY 24Effect of substrate concentration
velocity
(s)
V
max