$$\text{Glucose} + 2\,\text{ATP} \rightarrow 2\,\text{pyruvic acid} + 4\,\text{ATP} + 2\,\text{NADH} + 2\,\text{H}_2\text{O}$$

Question 1

Which of the following best describes a redox reaction in biological systems?

Accepted Answer

A reaction where electrons are transferred from one molecule to another, often accompanied by the transfer of hydrogen atoms.

Question 2

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

Accepted Answer

$$2$$

Question 3

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

Accepted Answer

$$O_2$$

Question 4

In the electron transport chain, what is the primary purpose of transferring electrons through a series of carriers?

Accepted Answer

To release energy used to pump protons and generate ATP via chemiosmosis.

Question 5

Which process is responsible for the majority of ATP production during aerobic respiration?

Accepted Answer

Oxidative phosphorylation

Question 6

What is the role of NAD+ in cellular respiration?

Accepted Answer

It acts as an electron carrier, accepting electrons during redox reactions.

Question 7

Which of the following statements about anaerobic respiration is correct?

Accepted Answer

The final electron acceptor is not $$O_2$$, and less ATP is produced compared to aerobic respiration.

Question 8

In substrate-level phosphorylation, ATP is generated by:

Accepted Answer

The direct transfer of a phosphate group from a high-energy substrate to ADP.

Question 9

Which stage of carbohydrate catabolism produces the most NADH?

Accepted Answer

Krebs cycle

Question 10

A bacterium is growing in an environment without oxygen but still produces ATP using an electron transport chain. Which process is it using?

Accepted Answer

Anaerobic respiration

Question 11

Which of the following equations correctly represents the net reaction of glycolysis?

Accepted Answer

$$	ext{Glucose} + 2\,	ext{ATP} ightarrow 2\,	ext{pyruvic acid} + 4\,	ext{ATP} + 2\,	ext{NADH} + 2\,	ext{H}_2	ext{O}$$

Question 12

Which of the following best explains why FADH2 produces less ATP than NADH during the electron transport chain?

Accepted Answer

FADH2 donates electrons further down the electron transport chain, resulting in fewer protons being pumped and less ATP generated.

Question 13

Which process occurs only in cells with light-trapping pigments such as chlorophyll?

Accepted Answer

Photophosphorylation

Question 14

A patient’s muscle cells are deprived of oxygen during intense exercise. Which metabolic pathway will primarily generate ATP in these cells?

Accepted Answer

Glycolysis followed by lactic acid fermentation

Question 15

Which of the following is a correct statement about the preparatory stage of glycolysis?

Accepted Answer

Two ATP molecules are used to phosphorylate glucose and its intermediates.

Question 16

In the conversion of lactate to pyruvate by lactate dehydrogenase, which molecule is reduced?

Accepted Answer

$$NAD^+$$

Question 17

Which of the following best describes the main function of the Krebs cycle?

Accepted Answer

To generate NADH and FADH2 for use in the electron transport chain.

Question 18

Which of the following is true regarding the energy yield from aerobic versus anaerobic respiration?

Accepted Answer

Aerobic respiration yields more ATP because oxygen is a more efficient final electron acceptor.

Question 19

Which of the following is a real-life application of substrate-level phosphorylation?

Accepted Answer

ATP generation during the conversion of phosphoenolpyruvate (PEP) to pyruvate in glycolysis.

Microbial Metabolism: Oxidation-Reduction, ATP Generation, and Carbohydrate Catabolism

Study Guide - Practice Questions