Question

Arsenate, AsO4 3- , a structural analog of phosphate, can act as a substrate for any reaction in which phosphate is a substrate. Arsenate esters hydrolyze instantaneously, so for example, the arsenate analog of ATP becomes ADP instantly. Given this information, which steps of glycolysis would be sensitive to arsenate and what would you predict would be the reason arsenate is a poison?

Answer 1

Phosphoglycerate kainase and pyruvate kainase are the steps involving the arsenate poisoning.

Step-by-step explanation:

In glycolysis, the glucose is broken down enzymatically with the help of NAD and ATP to produce the simpler 3 carbon product, the pyruvate. It is the 1st step of respiration which uses 2 molecules of ATP and 2 molecules of NAD to produce 4 molecules of ATP and 2 molecules of NADH.

The steps where ATP are produced are the steps where 1,3-bisphosphoglycerate changes to 3 phosphoglycerate with the help of enzyme Phosphoglycerate kainase and where phosphoenol pyruvate to pyruvate in presence of enzyme pyruvate kainase.

In presence of Arsenate, as arsenate mimics the phosphate, so these enzymes use arsenate in place of phosphate which acts as competitive inhibitor for phosphate and produces Adenosine diphosphate arsenate which quickly hydrolyzes to adenosine diphosphate. So the production of ATP falls, which leads to death.