Question

In a certain mutant strain of bacteria, the enzyme leucyl-tRNA synthetase mistakenly attaches isoleucine to leucyl-tRNA 10% of the time instead of attaching leucine. These bacteria will synthesize:

Answer 1

Answer:

The correct answer is "proteins in which isoleucine is inserted at some positions normally occupied by leucine".

Explanation:

The missing options of this question are:

A. proteins in which leucine is inserted at some positions normally occupied by isoleucine.

B. proteins in which isoleucine is inserted at some positions normally occupied by leucine.

C. no abnormal proteins, because the ribosomal translation machinery will recognize the inappropriately activated tRNAs and exclude them from the translation process.

D. no proteins, because the inappropriately activated tRNAs will block translation

The correct answer is option B. "proteins in which isoleucine is inserted at some positions normally occupied by leucine".

In normal conditions, the enzyme leucyl-tRNA synthetase attaches one leucine amino acid to leucyl-tRNA as part of synthesis of proteins that have one or more leucine residues in their sequences. Since the enzyme of this mutant strain of bacteria mistakenly attaches isoleucine to leucyl-tRNA 10% of the time, approximately 10% of all the proteins that normally have leucine residues will going to have isoleucine. Therefore, These bacteria will synthesize proteins in which isoleucine is inserted at some positions normally occupied by leucine.