Question

Imagine you do a version of the Beadle-Tatum experiment in which you attempt to test the one-gene, one-enzyme hypothesis, but using the pathway of synthesis of amino acid Q from X (below). The reactions, in order, are catalyzed by enzymes E1-E5. X is always present in cells, and cells need Q to grow. pathway You identify a mutant strain that doesn't grow in normal medium, but does grow in medium supplemented with Q, indicating that it has a defect in one or more enzymes in this pathway. This strain is also able to grow if you supplement the medium with Y. Which enzymes can you say with certainty are still functional (i.e. not disrupted by the mutation)

Answer 1

They would be the enzymes that assimilate the presence of Q to generate a metabolism that encourages growth.

And also those that are X-forming, which is what is always present in cells.

Step-by-step explanation:

Therefore, all the enzymes that assimilate the amino acid Q continue to function.

In simple words, in this situation, amino acid Q went from being a non-essential amino acid (because it was manufactured in-house) to being an essential amino acid (which, if or if, must be administered by the medium due to lack of own production in order to generate growth) .