Question

Find out the sequence of binding of the following amino acyl-t-RNA complexes during translation to a m-RNA transcribed by a DNA segment having the base sequence. 3' ATACCCATGGGG 5'.
Choose the answer showing the correct order of alphabets.

• A. a, b, c, d
• B. d, a, b, c
• C. a, b, d, c
• D. b, a, c, d

Answer 1

Answer: (B)

d, a, b, c

During protein synthesis, a succession of t-RNA molecules which are charged with appropriate amino acids are brought together with an m-RNA molecule and matched up by base pairing through the anticodons of the t-RNA with successive codons of the m-RNA. The given DNA sequence is 3' ATACCCATGGGG 5'. The corresponding m-RNA sequence will be 3' AUACCCAUGGGG 5'. The codons in the m-RNA are read in 3 alphabets. Hence, the first codon is AUA, the second is CCC, the third is AUG and the fourth will be GGG. Hence, the correct order of binding of the amino acyl t-RNA is d, a, b, c.