Question 1

Which of the following best describes positive feedback in a biochemical pathway?

Accepted Answer

A process where the end product accelerates its own production by enhancing the pathway.

Question 2

Which of the following is an example of a negative feedback mechanism in metabolism?

Accepted Answer

The accumulation of ATP inhibits phosphofructokinase in glycolysis.

Question 3

What is the role of an inhibitor in an enzymatic reaction?

Accepted Answer

To decrease the rate of product formation.

Question 4

Which equation best represents the Michaelis-Menten equation for enzyme kinetics?

Accepted Answer

$$v = \frac{V_{max}[S]}{K_m + [S]}$$

Question 5

A buildup of which molecule would most likely trigger a negative feedback loop in a metabolic pathway?

Accepted Answer

The final product

Question 6

Which of the following statements about allosteric inhibitors is correct?

Accepted Answer

They bind to a site other than the active site and decrease enzyme activity.

Question 7

If a pathway is regulated by both positive and negative feedback, what is the likely outcome?

Accepted Answer

The pathway will be tightly controlled, responding to both activation and inhibition signals.

Question 8

Which of the following best describes a substrate in an enzymatic reaction?

Accepted Answer

A molecule upon which an enzyme acts to form a product.

Question 9

Which of the following is a real-life example of positive feedback in human physiology?

Accepted Answer

Release of oxytocin during childbirth to intensify uterine contractions.

Question 10

Which of the following best describes the effect of a competitive inhibitor on enzyme kinetics?

Accepted Answer

It increases $$K_m$$ but does not affect $$V_{max}.$$

Question 11

A student observes that the product of a reaction inhibits an earlier enzyme in the same pathway. This is an example of:

Accepted Answer

Negative feedback

Question 12

Which of the following is most likely to occur if an inhibitor is removed from a metabolic pathway?

Accepted Answer

The pathway will speed up.

Question 13

Which of the following best describes the function of a feedback inhibitor?

Accepted Answer

It binds to the enzyme and decreases its activity when the product is abundant.

Question 14

Which of the following is a likely result of a mutation that prevents negative feedback in a metabolic pathway?

Accepted Answer

The pathway will be overactive, leading to excess product formation.

Question 15

Which of the following best describes the difference between an activator and an inhibitor?

Accepted Answer

An activator increases enzyme activity, while an inhibitor decreases it.

Feedback Mechanisms and Enzyme Regulation in Biochemistry

Study Guide - Practice Questions