Question Detail
Question
The insulin molecule is composed of two polypeptide chains, one consisting of 20 amino acids and the other consisting of 31. What is the minimum number of base pairs of DNA required to code for this molecule? A. 20 B. 51 C. 102 D. 153 E. 207
Correct Answer
Option D is the correct answer.
Detailed Explanation
Total amino acids = 20 + 31 = 51. Each amino acid is coded by a codon of 3 nucleotides (base pairs) on the DNA. So, nucleotides needed = 51 * 3 = 153. This is the minimum number of base pairs in the coding region of the DNA, not including introns or regulatory sequences.
Hint
Multiply the total number of amino acids by 3.