2. A biomolecule is any molecule that is present in
living organisms, they are divided into macro
molecules and micro molecules as follows:-
MACROMOLECULES
M > 1000
EXAMPLES
1. Polysaccharides
2. Nucleic acids
3. Proteins
MICROMOLECULES
M < 1000
EXAMPLES
1. Amino acids
2. Sugars
3. Nucleotides
4. Lipids
3. MACROMOLECULES
There are two kinds of Polysaccharides:
1. HOMOPOLYSACCHARIDES
CELLULOSE , STARCH
2. HETEROPOLYSACCHARIDES
CHITIN
POLYSACCHARIDES
4. NUCLEIC ACID
Function- transmits and stores genetic information
Composed of C, H, O, N & P (Phosphorous)
Two types
1. DNA
2. RNA
5. NUCLEIC ACIDS
Deoxyribonucleic acid
Contains the sugar deoxyribose
Double stranded
Ribonucleic acid
Contains the sugar ribose
Single stranded
6. PROTIENS
Polymers of amino acids
Organic compound made up of : Carbon Hydrogen Oxygen and Nitrogen
Proteins are essential to living things:
Proteins are needed to build & maintain cells, digest food, growth, insulin,
antibodies for immunity, transmit heredity, movement.
Examples of Proteins: ◊ Haemoglobin – carries O2 ◊ Actin – muscle
contraction ◊ Saliva (Enzyme) – breakdown Carbohydrates. ◊ Lactase
(Enzyme) – digest lactose sugar
Four Levels of Protein Structure
1. The primary structure of a protein is its unique sequence of amino acids
2. Secondary structure, found in most proteins, consists of coils and folds in
the polypeptide chain
3. Tertiary structure is determined by interactions among various side
chains (R groups)
4. Quaternary structure results when a protein consists of multiple
polypeptide chains Animation
7.
8. MICRO MOLECULES
There are 20 different amino acids that are incorporated into proteins.
All amino acids have an Amino Group (NH2), a Carboxyl group (COOH), and an
R-Group (unique side chain that distinguishes that amino acid).
Amino acids differ in their properties due to differing side chains, called R
groups
The sequence of amino acids determines a protein’s three-dimensional
structure. A protein’s structure determines its function.
AMINO ACIDS
9.
10. SUGARS
Monosaccharides : simplest sugars, which cannot be hydrolysed further into
smaller sugars
Composed of 3-7 C atoms
1. Triose (3C) (Glyceraldehyde)
2. Tetrose (4C) (Erythrose)
3. Pentose (5C) (Ribose)
4. Hexose (6C) (Glucose)
5. Heptose (7C) (Sedoheptulose)
Oligosaccharides : when 2/ few monosaccharides are combined by glycosidic
bonds.They are named as:
1. Disaccharides (2) : Sucrose
2. Trisaccharides (3) : Arabinose
3. Tetrasaccharides (4) :Stachyose
4. Pentasaccharides (5) : Verbascose
11.
12. NUCLEOTIDES
Nucleotides are organic molecules that serve as the monomers, or subunits,
of nucleic acids like DNA and RNA.
The building blocks of nucleic acids, nucleotides are composed of a
nitrogenous base, a five-carbon sugar (ribose or deoxyribose), and at least
one phosphate group.
Nitrogenous base attached to pentose sugar – adenosine, guanosine ,
thymidine, cytidine & uridine.
13.
14. LIPIDS
Fats, oils, waxes, steroids (examples)
Are made mostly of carbon, hydrogen, and oxygen
Are not soluble in water (they are nonpolar)
Hydrogen : oxygen ratio is greater than 2:1
Functions of Lipids
1. Used to store energy
2. Important part of biological membranes
There are two type:
1. Saturated Lipids : Solid fats, animals
2. Unsaturated Lipids: Oils, plants
Steroids are lipids characterized by a carbon skeleton consisting of four fused
rings . Cholesterol, an important steroid, is a component in animal cell
membranes . Although cholesterol is essential in animals, high levels in the
blood may contribute to cardiovascular disease.
