AP BIOLOGY

Detailed explanation-1: -Purines (adenine and guanine) are two-carbon nitrogen ring bases while pyrimidines (cytosine and thymine) are one-carbon nitrogen ring bases. Given below in a tabular column are the differences between Purines and Pyrimidines.

Detailed explanation-2: -There are two main types of purine: Adenine and Guanine. Both of these occur in both DNA and RNA.

Detailed explanation-3: -The chemical structures of A, G, C, T, and U are shown in (Fig. 1.5A). Because of their structural similarity, we usually refer the nine-member double rings adenine and guanine as purines, and six-member single-ring thymine, uracil, and cytosine are pyrimidines.

Detailed explanation-4: -There are four nucleotides, or bases, in DNA: adenine (A), cytosine (C), guanine (G), and thymine (T). These bases form specific pairs (A with T, and G with C).

Detailed explanation-5: -Adenine is one of the two purine nucleobases used in forming nucleotides of the nucleic acids. In DNA, adenine binds to thymine via two hydrogen bonds to assist in stabilizing the nucleic acid structures. In RNA, which is used in the cytoplasm for protein synthesis, adenine binds to uracil.