Academic Integrity: tutoring, explanations, and feedback — we don’t complete graded work or submit on a student’s behalf.

A student is trying to determine the mechanism for a reaction that uses ATP to a

ID: 514991 • Letter: A

Question

A student is trying to determine the mechanism for a reaction that uses ATP to activate a carboxylate ion, which then reacts with a thiol. If the carboxylate ion attacks the gamma-phosphorus of ATP, the reaction products are the thioester, ADP, and phosphate. However, whether it attacks the alpha-phosphorus or the beta-phosphorus of ATP cannot be determined from the reaction products because the thioester, AMP, and pyrophosphate would be the products in both reactions. The mechanisms can be distinguished by a labeling experiment in which the enzyme, the carboxylate ion, pyrophosphate, and radioactively labeled AMP are incubated, and ATP is isolated. What would be the results of the experiment? Match the words in the left column to the appropriate blanks in the sentences on the right. Make certain each sentence is complete before submitting your answer.

Explanation / Answer

Solution:

For alpha mechanism --> will not become, not a reactant

For beta mechanism --> will become, reactant

The ATP becomes radioactive under the presence (or) influence by P-glycerate kinase ( resemblance of mitochondria reaction).