Question

The codon for methionine (Met) is _____, the anticodon is _____, and the coding strand of DNA will read _____.

	a.	3' AUG 5'; 5' UAC 3'; 3' ATG 5'
	b.	5' AUG 3'; 5' UAC 3'; 5' ATG 3'
	c.	5' AUG 3' ; 3' UAC 5'; 3' ATG 5'
	d.	5' AUG 3'; 3' UAC 5'; 3' TAC 5'
	e.	5' AUG 3' ; 3' UAC 5'; 5' ATG 3'

Answer 1

Answer : Option e) 5' AUG 3' ; 3' UAC 5'; 5' ATG 3

Explanation:

The RNA polymerase enzyme synthesize the RNA in 5' to 3' direction. The template strand of DNA runs in 3' to 5' direction and the coding strand of DNA will be in the opposite direction of the template strand, that is 5' to 3'. The mRNA codon for methionine is 5' AUG 3' and the corresponding tRNA will be complementary to this codon. Hence the sequence of tRNA will be 3' UAC 5'. The sequence of the mRNA will be complementary to the template strand and will be same as the coding strand except for the nucleotide 'T'. In the mRNA 'U' nucleotide will be present instead of 'T'. So, the corresponding codon in the coding DNA will be 5' ATG 3'.