Question

_______ is/ are essential in nucleic acid synthesis.

• A. \( \text{Purines and pyrimidines} \)
• B. \( \text{Vitamins} \)
• C. \( \text{Metals} \)
• D. \( \text{Amino acids} \)

Hint:

To remember the groups, use the phrase: "CUT the PY" for Pyrimidines (Cytosine, Uracil, Thymine).

Answer 1

The Correct Option is A

Concept: Nucleic acids, namely DNA and RNA, are the primary information-carrying molecules in all living cells.
• Nucleic acids are composed of monomers called nucleotides.
• Each nucleotide consists of a phosphate group, a 5-carbon sugar, and a nitrogenous base.

Step 1: Structural components of nucleotides.
The nitrogenous bases are the most critical components for the genetic code. These bases are divided into two chemical categories: Purines and Pyrimidines.

Step 2: Role in synthesis.
During the process of biosynthesis, the cell must have a steady supply of these bases. Adenine and Guanine (Purines) along with Cytosine, Thymine, and Uracil (Pyrimidines) form the backbone of genetic synthesis. Without these specific nitrogenous compounds, the polymer chains of DNA or RNA cannot be constructed.