Question 1

Which of the following best describes the role of enzymes in biological reactions?

Accepted Answer

Enzymes lower the activation energy, allowing reactions to proceed more rapidly.

Question 2

A competitive inhibitor affects an enzyme-catalyzed reaction by:

Accepted Answer

Binding to the active site and preventing substrate binding.

Question 3

Which of the following is the correct overall equation for aerobic cellular respiration?

Accepted Answer

$$\mathrm{C}_6\mathrm{H}_{12}\mathrm{O}_6 + 6\ \mathrm{O}_2 ightarrow 6\ \mathrm{CO}_2 + 6\ \mathrm{H}_2O + 	ext{energy (ATP)}$$

Question 4

Which molecule acts as the final electron acceptor in the electron transport chain during aerobic respiration?

Accepted Answer

O$$_2$$

Question 5

What is the main purpose of fermentation in muscle cells during intense exercise?

Accepted Answer

To regenerate NAD$$^+ so $$glycolysis can continue.

Question 6

Which of the following best explains why ATP is considered the 'energy currency' of the cell?

Accepted Answer

ATP contains high-energy phosphate bonds that can be hydrolyzed to release energy.

Question 7

Which step of cellular respiration produces the most ATP?

Accepted Answer

Electron transport chain and chemiosmosis

Question 8

A poison that binds to and inhibits ATP synthase would directly prevent which process?

Accepted Answer

The synthesis of ATP from ADP and Pi during chemiosmosis

Question 9

Which of the following statements about enzyme denaturation is correct?

Accepted Answer

Denaturation can be caused by extreme pH or high temperature.

Question 10

Which of the following is an example of feedback inhibition?

Accepted Answer

A product of a metabolic pathway binds to an enzyme early in the pathway and decreases its activity.

Question 11

Which of the following best describes the process of substrate-level phosphorylation?

Accepted Answer

ATP is produced directly by transferring a phosphate group from a substrate to ADP.

Question 12

Which of the following would most likely increase the rate of pyruvate processing?

Accepted Answer

High amounts of NAD$$^+$$ relative to NADH

Question 13

Which of the following is NOT an output of pyruvate processing?

Accepted Answer

ATP

Question 14

If a cell is exposed to cyanide, which blocks the electron transport chain, what will be the immediate effect?

Accepted Answer

Electron flow to oxygen will stop, halting ATP production by oxidative phosphorylation.

Question 15

Which of the following best explains why oxygen is the most effective final electron acceptor in the electron transport chain?

Accepted Answer

Oxygen is highly electronegative, allowing it to pull electrons through the chain efficiently.

Question 16

Which of the following is a correct description of the induced fit model of enzyme action?

Accepted Answer

The enzyme changes shape slightly to better fit the substrate upon binding.

Question 17

Which of the following is true about the regulation of glycolysis?

Accepted Answer

High levels of ATP inhibit phosphofructokinase, slowing glycolysis.

Question 18

Which of the following statements about NAD$$^+$$ and NADH is correct?

Accepted Answer

NAD$$^+ is $$reduced to NADH during glycolysis and the citric acid cycle.

Question 19

During heavy exercise, your muscle cells switch to lactic acid fermentation. What is the main reason for this switch?

Accepted Answer

Oxygen is not available as the final electron acceptor.

Enzymes, Energy, and Cellular Respiration: Study Guide

Guida di studio - Domande di pratica