Question

Identify two structural features of purines and pyrimidines.

Purines

__contain two heterocyclic rings.
__contain only two ring nitrogen atoms.
__contain four ring nitrogen atoms.
__contain one heterocyclic ring.
__contain only three ring nitrogen atoms.

Pyrimidines

__contain one heterocyclic ring.
__contain four ring nitrogen atoms.
__contain only three ring nitrogen atoms.
__contain two heterocyclic rings.
__contain only two ring nitrogen atoms.

Answer 1

Purines and pyrimidines are the nitrogenous bases of the nucleic acids and act as the building blocks of the DNA and RNA.

They both show structural differences between them as the-

Purines :

1. contain only four ring nitrogen atoms.

2. contain two heterocyclic rings.

Pyrimidines:

1. contain only two ring nitrogen atoms.

2. contain one heterocyclic ring