3. Carbohydrates.
Carbohydrates are always composed of
Carbon, Hydrogen and Oxygen atoms.
All have general formula Cx(H2O)y
(hydrates (H2O) of carbon).
The ratio between H and O atoms is
always 2:1
Carbohydrates can be divided into 4 main
groups. They are Monosaccharides,
Disaccharides, Oligosaccharides and
Polysaccharides.
4. A monosaccharide is a carbohydrate that cannot
be reduced by hydrolysis into another simple
sugar. Over 200 different monosaccharides are
known.
A disaccharide formed by two monosaccharide
molecules link by glycosidic bond.
An oligosaccharide formed by 3-10
monosaccharide molecules link by glycosidic bond.
A polysaccharide formed by more than10
monosaccharide molecules link by glycosidic bond.
5. Monosaccharides.
Monosaccharides or simple sugars can't be
converted into smaller sugars by hydrolysis.
No. of Carbons :- 3= triose
No. of Carbons :- 4= tetrose
No. of Carbons :- 5= pentose
No. of Carbons :- 6= hexose
No. of Carbons :- 7= heptose
Can be an aldose or ketose
7. Pentose
Important to form Ribonucleotides.
Ribonucleotides are the monomer of
RNA molecule.
Ribose is also important in the creation
of ATP that all cells require to stay
alive.
Important to form Deoxy
ribonucleotides. Deoxy
ribonucleotides are the
monomer of DNA molecule.
13. Disaccharides.
A disaccharide formed by two monosaccharide molecules link by
glycosidic bond
Disaccharides which we consider here are Maltose, Cellobiose,
Sucrose, and Lactose
Maltose
Alpha Glucose Alpha Glucose Maltose
α (1 4) glycosidic
bond
16. Polysaccharides.
A polysaccharide formed by more than10 monosaccharide
molecules link by glycosidic bond.
Polysaccharides which we consider here are Starch, Glycogen
and Cellulose.
Starch
Starch consist of two polysaccharide molecules. They are amylose and
amylopectin.
α (1 4) glycosidic
bond
α (1 6) glycosidic
bond
17. Glycogen
Glycogen consist of highly branched amylopectin.
Cellulose
Cellulose is a linear polysaccharide in which about
1500 beta glucose rings link together.
β (1 4) glycosidic
bond
19. Proteins.
• The most abundant biological
macromolecules, occurring in all cells and
all parts of cells.
• Made up of chains of amino acids.
• Occur in great variety.
• Involved in most of the body’s functions and
life processes.
The sequence of amino acids is determined by
DNA
Proteins are,
20. Amino Group (-NH2)
Carboxylic Acid Group (-COOH)
A generalized Amino acid
The amino group is one of the
reasons why nitrogen is an
important element in living
things.
The carboxylic acid group contains
an oxygen double-bonded to the
carbon and a hydroxyl group (-OH)
that can be lost to form new bonds.
The basic structure of the amino acids is common. There are 22 different
protein-making amino acids, though only 20 are coded for in genetic code.
Each has its own unique R-group. Some R groups are polar, others non-polar
and their different properties determine their interactions and the shape of
the final protein.
21. Two amino acid molecules can be covalently joined
through a peptide bond, to yield a dipeptide.
Such a linkage is formed by removal of the elements
of water (dehydration) from the α-carboxyl group of
one amino acid, and the α–amino group of another.
23. Three amino acids can be joined by two peptide
bonds to form a tripeptide; similarly, amino acids
can be linked to form tetrapeptides,
pentapeptides, and so on.
When many amino acids are joined, the product is
called a polypeptide.
Proteins may have thousands of amino acid units.
Although the terms “protein” and “polypeptide”
are sometimes used interchangeably, molecules
referred to as polypeptides generally have
molecular weights below 10,000, and those called
proteins have higher molecular weights.
24. Protein Structure
• The 3-D shape and properties of the
protein determine its function.
• Shape and properties of protein
determined by interactions between
individual amino acid components.
• There are four levels of protein
structure. They are, primary (Io),
secondary (IIo), tertiary (IIIo), and
quaternary (IVo).
25. Primary Structure
The primary structure of a protein refers to the
linear sequence of amino acids in the polypeptide
chain.
26. Secondary Structure
• Protein secondary structure is the three
dimensional form of local segments of protein.
In secondary structure, the CO group of one
amino acid (n) is hydrogen bonded to the NH
group of the amino acid four residues away (n
+4).
• The two most common secondary structural
elements are alpha helices and beta sheets.
• Beta sheets have two types. They are parallel
and antiparallel.
28. Parallel beta sheet
In parallel beta sheet, strands are oriented such
that, N --> C directions are the same
29. Antiparallel beta sheet
In antiparallel beta sheet, strands are oriented such
that N --> C directions are opposite.
30. Tertiary Structure
• The overall three-dimensional shape of an entire
protein molecule is the tertiary structure. The
protein molecule will bend and twist in such a
way as to achieve maximum stability or lowest
energy state.
• Although the three-dimensional shape of a
protein may seem irregular and random, it is
composed by many stabilizing forces due to
bonding interactions between the side-chain
groups of the amino acids.
31.
32. Quaternary Structure
• Quaternary structure is the three-dimensional structure of a
multi-subunit protein.
• Complexes of two or more polypeptides (i.e. multiple subunits)
are called multimers.
• Specifically it would be called a dimer if it contains two
subunits, a trimer if it contains three subunits, a tetramer if it
contains four subunits, and a pentamer if it contains five
subunits.
• Multimers made up of identical subunits are referred to with a
prefix of "homo" (e.g. a homotetramer) and those made up of
different subunits are referred to with a prefix of "hetero". For
example, a heterotetramer, such as the two alpha and two
beta chains of hemoglobin.
34. Functions of Proteins.
• Structure :- Form structural components of the cell including:
– Cytoskeleton / nuclear matrix / tissue matrix
• Elastin, collagen, keratin
• Movement :- Coordinate internal and external movement of cells,
organells, tissues, and molecules.
– Muscle contraction, chromosome separation, flagella.
• Tubulin, actin, myosin
• Transport :-Regulate transport of molecules into and out of the cell
/ nucleus / organelles.
• Channels, receptors, dynin, kinesin
• Communication :-Serve as communication molecules between
different organelles, cells, tissues, organs, organisms.
– Hormones
35. • Chemical Catalyst :– Serves to make possible all of
the chemical reactions that occur within the cell.
– Enzymes (thousands of different enzymes)
• Defense :-Recognize self and non-self, able to
destroy foreign entities (bacteria, viruses, tissues).
– Antibodies, cellular immune factors
36. • Lipids are any of a class of organic compounds,
that are fatty acids or their derivatives and are
insoluble in water but soluble in organic solvents.
They include many natural oils, waxes, and
steroids.
• The chemical composition of these molecules
includes Hydrogen, Carbon, and Oxygen.
• They provide high energy and perform three
important biological functions in the body, such as,
to provide structure to cell membranes, to store
energy, and to function as signalling molecules.
Lipids.
37. A. Simple lipids or homolipids :- Ester of fatty acids with
various alcohols
1. Natural fats and oils (triglycerides)
2. Waxes
B. Compound lipids or heterolipids :- Esters of fatty acids with
alcohol plus other groups
1. Phospholipids : Contains phosphoric acid.
2. Spingolipids : Contains a set of aliphatic amino alcohols that
includes sphingosine.
3. Glycolipids: They are lipids with a carbohydrate attached
by a glycosidic bond.
4. Sulfolipids : Contains sulfate group.
5. Lipoproteins : Lipids attached to plasma/other proteins.
Classification
38. C. Derived lipids :– They are the substances produced
from simple and compound lipids through the process
of hydrolysis.
1. Terpenes
2. Steroids
3. Carotenoids
39. Triglycerides
Triglycerides: the major class of dietary
lipids.
Made up of 3 units known as fatty acids and 1 unit called glycerol.
Comprise about 95% of lipids in food and the human body.
Include Fats and Oils.
Fat: solid at room temperature
Oil: liquid at room temperature
40. There are two types of fatty acids.
They are,
1. Saturated fatty acids, and
2. Unsaturated fatty acids
A saturated fatty acid.
42. 1. A saturated fatty acid is a fatty acid in which
carbon chain contains no unsaturated linkages
between carbon atoms, and hence cannot
incorporate any more hydrogen atoms.
2. An unsaturated fatty acid is a fatty acid in which
there is at least one double bond within the fatty
acid chain. A fatty acid chain is monounsaturated if
it contains one double bond, and polyunsaturated
if it contains more than one double bond.
47. Phospholipids consist of a glycerol molecule, two fatty acids, and a
phosphate group that is modified by an alcohol.
The phosphate group is the negatively-charged polar head, which is
hydrophilic.
The fatty acid chains are the uncharged, nonpolar tails, which are
hydrophobic.
Phospholipids
Phospholipids are a major component of all cell membranes.
49. Steroid
A steroid is an organic compound with four rings arranged in a
specific configuration.
Examples include the dietary lipid cholesterol, and the anti
inflammatory drug dexamethasone.
Steroids have two principal biological functions:
1. Certain steroids (such as cholesterol) are important
components of cell membranes which alter membrane fluidity.
2. Many steroids are signaling molecules which activate steroid
hormone receptors.
51. Functions of Lipids.
• Lipids are storage compounds, triglycerides serve as reserve energy of
the body.
• Lipids are important component of cell membranes structure in
eukaryotic cells.
• Lipids regulate membrane permeability.
• They serve as source for fat soluble vitamins like A, D, E, K.
• They act electrical insulators to the nerve fibers, where the myelin
sheath contains lipids.
• Lipids are components of some enzyme systems.
• Some lipids like prostaglandins and steroid hormones act as cellular
metabolic regulators.
52. • As lipids are small molecules and are insoluble in water, they act as
signalling molecules.
• Layers of fat in the subcutaneous layer, provides insulation and
protection from cold.
• Polyunsaturated phospholipids are important constituents of
phospholipids, they provide fluidity and flexibility to the cell
membranes.
• Lipoproteins that are complexes of lipids and proteins, occur in blood
as plasma lipoprotein. They enable transport of lipids in aqueous
environment, and their transport throughout the body.
• Cholesterol maintains fluidity of membranes by interacting with
lipid complexes.
53. Nucleic acids.
Nucleic acids are a complex organic substance present in all living cells,
whose molecules consist of many nucleotides linked in a long chain.
They are biopolymers, or large biomolecules, essential for all known forms
of life.
There are two types of nucleic acids, they are DNA (Deoxyribonucleic acid)
and RNA (Ribonucleic acid).
Nucleic acids are made from monomers known as nucleotides. Each
nucleotide has three components: A 5-carbon sugar, a phosphate group, and
a nitrogenous base.
If the sugar is deoxyribose, the polymer is DNA. If the sugar is ribose,
the polymer is RNA.
54.
55. Deoxyribonucleic acid
Deoxyribonucleic acid, is a molecule that carries
the genetic instructions used in the all metabolic
activities of all known living organisms, and
many viruses.
It is a very long, double stranded molecule made up
of monomers know as deoxy ribonucleotide.
56. They are the monomer of DNA.
They have three parts which shown in following
diagram.
Deoxyribose sugar
Phosphate group
Nitrogen base
Deoxy ribonucleotide
58. There are four different bases found in
DNA. Because each base contains at least
two nitrogen atoms, they are called
nitrogenous bases.
Nitrogenous Bases
There are two classes
of bases:
59. • DNA consists of two polynucleotide chains
wound around each other to form a double
helix.
• The double helix is the three-dimensional
structure of double stranded DNA.
• The two chains are held together by
complementary base pairing; that is,
hydrogen bonding between A and T bases,
and between G and C bases on the two
strands.
A double helix
60. • The two DNA strands are oriented in opposite directions.
61. Polynucleotide chains
A DNA chain consists of nucleotides
joined by sugar phosphate/ phospho
diester bonds, between phosphate and
sugar.
This makes up the sides of the DNA
“ladder”.
63. Complementary base
pairing involves
specific hydrogen
bonding between A and
T bases (two bonds),
and between G and C
bases (three bonds).
These paired bases
form the rungs of the
DNA “ladder”.
64. DNA is vital for all living beings. It is
important for inheritance, coding for
proteins and the genetic instruction guide for
life and its processes. Its simple structure
holds the key to millions of different genetic
codes for all of the species of life on The
Earth.
DNA holds the instructions for all metabolic
activities of an organism's or each cell.
Functions of DNA.
65. Enzymes
Enzymes are biological catalysts, and they are
proteins, generated by an organism to speed up
chemical reactions occurring in the body.
They can be described as any of several complex
proteins that are produced by cells and act as
catalysts in specific biochemical reactions.
Biological catalysts are those catalysts which are
found in living organisms and they speed up the
metabolic reactions occurring in them.
66. Catalyst
A catalyst is a substance that speeds up the rate of a
chemical reaction but is not itself changed by the
reaction.
A substance that lowers activation energy of a reaction
so the reaction occurs more quickly but, in the end, is
NOT used up by the reaction is called a catalyst.
Enzymes act as biological catalysts.
They occur inside cells or are secreted by the cells.
67. Activation Energy
To start any chemical reaction, energy
is required. The minimum amount of
energy required to start a reaction is
known as it activation energy.
Activation Energy can be defined as
the energy that must be added to
molecules to react with one another.
69. Characteristics of Enzymes
1)Speed up chemical reactions
2)Are required in small amounts
3)Are highly specific in their action
4)Are affected by temperature of the medium
5)Are affected by pH of the medium
6)Some catalyse reversible reactions
7)Some require co-enzymes
8)Are inhibited by inhibitors
70. 9) Unstable for heat
10) Water soluble
11) Deficiency or lack will lead to inborn
errors of metabolism
71. Uses of enzymes in daily life
Enzymes are produced in living organisms by
cells. But the enzymes used for commercial
purposes are synthetic and made in industries.
Enzymes are used in:
1. Bread production.
2. Fermentation.
3. Paper production.
4. Production of cleaning products (detergent
etc.)
72. Some Enzymes And Their
Applications
APPLICATION ENZYMES USED
Food processing Amylase,Protease
Baby food Trypsin
Brewing industry Amylase,Protease
Fruit juices Cellulase,Pectinases
Dairy industry Lipases,Lactases
Paper industry Amylase,Ligninase,
Xylanases,Cellulases
Biological detergent Amylase,Lipase,Cellulases
Rubber industry Catalase
Photographic industry Protease
