Question

Wobble hypothesis was proposed by

• A. Holley
• B. Nirenberg
• C. Khorana
• D. Crick

Answer 1

The correct option is D Crick

Wobble hypothesis was proposed by Crick. Accordingly, there is a strong base pairing between first two bases of an mRNA codon and corresponding bases of the tRNA anticodon which in turn confer most of the coding specificity. The first base of the anticodon (5’-3’direction that pairs with the third base of the codon) determines the number of codons recognized by the tRNA. The presence of C or A at first position confers specific base pairing and only one codon is recognized by that tRNA. The presence of U or G at this position means less specific and two different codons may be read. The presence of inosine (I) is the first (wobble) nucleotide of an anticodon, three different codons can be recognized. If multiple codons, coding for same amino acid, differ in either of the first two bases different tRNAs are required by each codon. The wobble (or third) base of the codon contributes to specificity and its loose base pairing with the corresponding base in the anticodon permits rapid dissociation of the tRNA from its codon during protein synthesis. The correct answer is D.