$$C_6H_{12}O_6$ + 6O_2 \rightarrow 6CO_2 + 6H_2O + \text{Energy}$$

Question 1

Which of the following best describes a catabolic pathway in cellular metabolism?

Accepted Answer

A pathway that breaks down complex molecules into simpler ones, releasing energy.

Question 2

During cellular respiration, which molecule is the primary electron donor in redox reactions?

Accepted Answer

Glucose ($$C_6H_{12}O_6$)

Question 3

In the equation $$C_6H_{12}O_6$ + 6O_2 ightarrow 6CO_2 + 6H_2O + 	ext{Energy}$$, which molecule is reduced?

Accepted Answer

Oxygen ($$O_2)$$

Question 4

Which mnemonic helps you remember the difference between oxidation and reduction in redox reactions?

Accepted Answer

LEO the lion says GER: Loss of Electrons is Oxidation, Gain of Electrons is Reduction

Question 5

Why is glucose typically the starting molecule for glycolysis in most living cells?

Accepted Answer

It is present and ubiquitous in almost all living cells and has a central role in metabolism.

Question 6

Which of the following is a correct summary of the products generated from one molecule of glucose after glycolysis and the citric acid cycle?

Accepted Answer

$$4$$ ATP, $$10$$ NADH, $$2$$ $$FADH_2$

Question 7

What is the main purpose of the citric acid cycle in cellular respiration?

Accepted Answer

To extract high-energy electrons by producing NADH and $$FADH_2.$$

Question 8

During glycolysis, which phase is responsible for the net production of ATP?

Accepted Answer

Energy generation phase (steps 6-10)

Question 9

Which molecule is formed when pyruvate is transported into the mitochondrial matrix and one carbon is removed?

Accepted Answer

Acetyl-CoA

Question 10

If a cell is unable to produce NAD+, which process would be directly affected first?

Accepted Answer

Glycolysis

Question 11

Which of the following is a waste product generated by the citric acid cycle?

Accepted Answer

Carbon dioxide ($$CO_2)$$

Question 12

Which reduced intermediates are produced during the citric acid cycle and later used in the electron transport chain?

Accepted Answer

NADH and $$FADH_2$$

Question 13

A mutation prevents the removal of a carbon from pyruvate during its transport into the mitochondria. What is the most immediate consequence?

Accepted Answer

Acetyl-CoA cannot be formed, halting the citric acid cycle.

Question 14

Which of the following best explains why redox reactions are essential for cellular respiration?

Accepted Answer

They enable the transfer of electrons, which is necessary for ATP production.

Question 15

In a scenario where oxygen is not available, which process will be most affected in an animal cell?

Accepted Answer

Citric acid cycle

Question 16

Which of the following equations correctly represents the overall reaction for aerobic cellular respiration?

Accepted Answer

$$C_6H_{12}O_6$ + 6O_2 ightarrow 6CO_2 + 6H_2O + 	ext{Energy}$$

Question 17

Which molecule acts as an electron carrier during both glycolysis and the citric acid cycle?

Accepted Answer

NAD+

Question 18

A patient is diagnosed with a deficiency in FAD. Which stage of cellular respiration would be most directly impaired?

Accepted Answer

Citric acid cycle

Question 19

Which of the following is NOT a direct product of glycolysis?

Accepted Answer

$$FADH_2$$

Question 20

If a cell accumulates excess NADH and $$FADH_2$$ but cannot use them, which process is most likely malfunctioning?

Accepted Answer

Electron transport chain

Cellular Respiration: Glycolysis and the Citric Acid Cycle

Study Guide - Practice Questions