BIOMOLECULES AND ENZYMES

Detailed explanation-1: -The purines (adenine and guanine) have a two-ringed structure consisting of a nine-membered molecule with four nitrogen atoms, as you can see in the two figures below. The pyrimidines (cytosine, uracil, and thymine) only have one single ring, which has just six members and two nitrogen atoms.

Detailed explanation-2: -Purines have a double ringed aromatic structure. Adenine and guanine are examples of purines. Pyrimidines have a single ringed structure. Cytosine, thymine and uracil are examples of pyrimidine.

Detailed explanation-3: -Purine bases (double ring structures) are adenine and guanine.

Detailed explanation-4: -Adenine (A) and guanine (G) are double-ringed purines, and cytosine (C) and thymine (T) are smaller, single-ringed pyrimidines.

Detailed explanation-5: -Pyrimidines are nitrogenous bases with 1 ring structure, whereas purines are nitrogenous bases with 2 ring structures.