Question

Define the following terms :

(i) Nucleotides

(ii) Anomers

(iii) Essential amino acids

Answer 1

(i) Nucleotides : These are the monomeric units of a type of long polymers called nucleic acids. These are compounds of three components i.e., nitrogen containing heterocyclic bases, a five carbon sugar and a phosphorus moiety.

$\stackrel{Base}{\stackrel{|}{Sugar}}-O-\stackrel{\stackrel{O}{||}}{\underset{\underset{OH}{|}}{P}}-OH$

(ii) Anomers: A pair of stereoisomers which differ in configuration only around $C_1$ are called anomers. e.g., $\alpha$-D-glucose and $\beta$ -D-glucose are anomers. In $\alpha$-D-Glucose, the -OH group at $C_1$ carbon is towards right while in $\beta$ -D-glucose, the -OH group at $C_1$ is towards left.

(iii) Essential amino acids: The amino acids which cannot be synthesized by the body and must be obtained through diet, are known as essential amino acids.