Question

An amino acid is synthesized by the prokaryote, E coli. The genes for the enzymes responsible for synthesizing this amino acid are encoded in an operon. The operon is regulated by a repressor. When the amino acid binds to the repressor, the repressor changes shape so it can bind to the operator. Which of the following statements is true?

A) When levels of the amino acid are high, it binds to the repressor, allowing synthesis of this amino acid to proceed.
B) When levels of the amino acid are low, it binds to the repressor, allowing synthesis of this amino acid to proceed...

Answer 1

C) When the levels of amino acid are high, it binds to the repressor, ending the synthesis of the amino acid.
D) When levels of amino acid are low, it binds to the repressor, ending the synthesis of the amino acid.

Answer 2

It's C. Repressors inhibit further translation of the mRNA, and since the prompt stated that the amino acid itself is the initiating substrate, we can conclude that high quantities of the amino acid represses the synthesis of the same amino acid. This is a common negative feedback loop.

Answer 3

Thank you!

Answer 4

You're welcome