Q: Which equation correctly represents the overall process of aerobic cellular respiration?

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

Q: Which of the following reactions represents the reduction of NAD+?

$$\text{NAD}^+ + 2H^+ + 2e^- \rightarrow \text{NADH} + H^+$$

Question 1

Which of the following statements best describes the role of NAD+ in cellular respiration?

Accepted Answer

NAD+ serves as an electron carrier, accepting electrons during redox reactions to become NADH.

Question 2

During glycolysis, what is the net gain of ATP and NADH molecules per molecule of glucose?

Accepted Answer

2 ATP and 2 NADH

Question 3

Which equation correctly represents the overall process of aerobic cellular respiration?

Accepted Answer

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

Question 4

A patient is experiencing muscle fatigue during intense exercise. Which metabolic pathway is most likely responsible for the production of lactate in their muscle cells?

Accepted Answer

Fermentation following glycolysis in the cytoplasm

Question 5

Which enzyme is primarily responsible for regulating the rate of glycolysis and is inhibited by high levels of ATP and citrate?

Accepted Answer

Phosphofructokinase

Question 6

In the Krebs cycle, what is the fate of the two carbon atoms from acetyl-CoA?

Accepted Answer

They are released as $$CO_2$$ during the cycle.

Question 7

Which of the following best explains why glycolysis can occur in both aerobic and anaerobic conditions?

Accepted Answer

Glycolysis does not require oxygen and occurs in the cytoplasm.

Question 8

Which molecule is regenerated during fermentation to allow glycolysis to continue in the absence of oxygen?

Accepted Answer

NAD+

Question 9

A mutation causes the enzyme pyruvate dehydrogenase to be nonfunctional. Which process would be directly affected?

Accepted Answer

Conversion of pyruvate to acetyl-CoA

Question 10

Which of the following is a correct description of substrate-level phosphorylation?

Accepted Answer

ATP is generated directly by transferring a phosphate group from a high-energy substrate to ADP.

Question 11

Which of the following reactions represents the reduction of NAD+?

Accepted Answer

$$	ext{NAD}^+ + 2H^+ + 2e^- ightarrow 	ext{NADH} + H^+$$

Question 12

If a cell is deprived of oxygen, which process will be directly inhibited, leading to a decrease in ATP production?

Accepted Answer

Electron transport chain

Question 13

Which of the following best describes the role of FAD in cellular respiration?

Accepted Answer

FAD is reduced to FADH2 during the Krebs cycle and donates electrons to the electron transport chain.

Question 14

Which of the following is a regulatory mechanism of phosphofructokinase in glycolysis?

Accepted Answer

It is inhibited by high levels of ATP and citrate.

Question 15

A yeast cell is placed in an anaerobic environment. Which end products will be produced from glucose metabolism?

Accepted Answer

Ethanol and $$CO_2$$

Question 16

Which step in glycolysis is considered irreversible and highly regulated?

Accepted Answer

Step 3, catalyzed by phosphofructokinase

Question 17

Which of the following best explains why ATP is considered to have high potential energy?

Accepted Answer

ATP contains three phosphate groups with unstable bonds that release energy when hydrolyzed.

Question 18

During the Krebs cycle, which molecule combines with acetyl-CoA to form citrate?

Accepted Answer

Oxaloacetate

Question 19

Which of the following is a correct summary of the products generated from one turn of the Krebs cycle?

Accepted Answer

3 NADH, 1 FADH2, 1 GTP, and 2 CO2

Cellular Respiration: Glycolysis and Krebs Cycle Study Notes

Study Guide - Practice Questions

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