Question

Feedback inhibition is important for the regulation of many metabolic pathways. Which of the statements are examples of feedback inhibition? The beginning of glycolysis is inhibited by high levels of ATP in the cell. The production of tryptophan is halted by the presence of excess tryptophan. An intermediate of glycolysis activates an enzyme downstream in the pathway. Arsenic binds to pyruvate dehydrogenase and inhibits the enzyme. The lac operon is not transcribed when there is no lactose present.

Answer 1

Answer:

• The beginning of glycolysis is inhibited by high levels of ATP in the cell.
• The production of tryptophan is halted by presence of excess tryptophan.

Explanation:

As you may already know, the feedback mechanism is extremely important as homeostasis, that is, the balance of our body. This mechanism is composed of a group of responses produced biologically to some stimulus that is causing an imbalance somewhere in the body.

However, the balance of our organism often needs to promote the inhibition of the feedback mechanism, mainly related to the overproduction of a certain molecule. Two examples that may show an inhibition of the feedback mechanism are:

• The beginning of glycolysis is inhibited by high levels of ATP in the cell.
• The production of tryptophan is halted by presence of excess tryptophan.