- Mutarotation: The gradual change of
optical rotation with time of a freshly prepared solution of sugar till
a constant value is obtained. The freshly prepared sample of D (+)
glucose has specific rotation of +112°. When the solution is allowed to
stand, the specific rotation falls to +52.7° and remains constant at
- Anomer: Pair of optical isomers
which differ only in the configuration of one carbon atom (C1)
in space are called anomers.
Example: a-D-glucose and b- D- glucose.
- Isoelectric Point: The pH at which the
structure of an amino acid has no net charge is called its isoelectric point.
- Denaturation: Loss of biological activity
of proteins by a physical or chemical change is denaturation.
- Primary Structure of
The unique sequence of amino acids in each kind of protein is called the
primary structure of proteins.
- Secondary Structure of
The three dimensional structure of polypeptides and proteins is the
secondary structure of proteins.
- Tertiary Structure of
The folding and bending of secondary structure of polypeptides and
proteins is the tertiary structure of proteins.
- Rancidity in Fats: Most fats on exposure to
air develop an unpleasant odour and flavour which is due to the partial hydrolysis of
fat leading to liberation of volatile acids which have an unpleasant odour.
- Lipids: The term lipid is for a
group of biomolecules which are insoluble in
water but are soluble in organic solvents of low polarity such as carbon
tetrachloride, chloroform, etc.
- Waxes: They are the lipids which
contain in them large amount of esters of long chain monohydric alcohols
(C16 - C36) with higher fatty acids.