$$ \text{PEP} + \text{ADP} \rightarrow \text{Pyruvate} + \text{ATP} $$

Question 1

Which of the following best describes the main purpose of glycolysis in cellular metabolism?

Accepted Answer

To split glucose into two molecules of pyruvic acid, generating ATP and NADH

Question 2

During the intermediate step of cellular respiration, what are the products formed from one molecule of glucose?

Accepted Answer

Two molecules of acetyl-CoA, two molecules of CO$$_2$$, and two molecules of NADH

Question 3

Which of the following equations correctly represents substrate-level phosphorylation as it occurs in glycolysis?

Accepted Answer

$$ 	ext{PEP} + 	ext{ADP} ightarrow 	ext{Pyruvate} + 	ext{ATP} $$

Question 4

Why is fermentation necessary in some cells under anaerobic conditions?

Accepted Answer

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

Question 5

Which of the following is a correct comparison between inhibitors and uncouplers of oxidative phosphorylation?

Accepted Answer

Inhibitors stop electron flow, while uncouplers allow electron flow but prevent ATP synthesis

Question 6

What is the net gain of ATP molecules produced by substrate-level phosphorylation during the complete oxidation of one molecule of glucose?

Accepted Answer

4 ATP

Question 7

Which of the following best explains why fermentation is less energetically efficient than cellular respiration?

Accepted Answer

Most of the potential energy remains in the bonds of fermentation products

Question 8

A patient is exposed to cyanide, which binds to the iron in cytochromes. What is the most immediate effect on cellular respiration?

Accepted Answer

Electron flow in the electron transport chain stops, halting ATP production

Question 9

Which of the following is the correct sequence of events for the complete oxidation of glucose in aerobic respiration?

Accepted Answer

Glycolysis → Intermediate step → Krebs cycle → Electron transport chain

Question 10

How many ATP equivalents are produced from the complete oxidation of one molecule of lauric acid (C-12 fatty acid)?

Accepted Answer

95 ATP

Question 11

Which of the following statements about the electron transport chain (ETC) is correct?

Accepted Answer

The ETC uses the energy from electron flow to pump protons across a membrane, creating a proton gradient

Question 12

Which of the following is a product of lactic acid fermentation?

Accepted Answer

Lactic acid

Question 13

What is the main function of beta oxidation in lipid catabolism?

Accepted Answer

To break down fatty acids into acetyl-CoA units for entry into the Krebs cycle

Question 14

Which shuttle system is used by most eukaryotic cells to transport cytosolic NADH into mitochondria for oxidative phosphorylation?

Accepted Answer

Glycerol phosphate shuttle

Question 15

Which of the following best describes the chemiosmotic theory of ATP synthesis?

Accepted Answer

ATP is synthesized as protons flow down their electrochemical gradient through ATP synthase

Question 16

A mutation prevents the regeneration of NAD$$^+ in a $$cell. Which metabolic pathway would be directly affected first?

Accepted Answer

Glycolysis

Question 17

Which of the following is a real-world example of a food product that relies on microbial fermentation for its production?

Accepted Answer

Chocolate

Question 18

How many ATP equivalents are produced from the complete oxidation of one triglyceride containing three palmitic acids (C-16 fatty acids)?

Accepted Answer

406 ATP

Question 19

Which of the following statements about oxidative phosphorylation is correct?

Accepted Answer

It occurs in the cytoplasm of prokaryotes and the mitochondrial inner membrane of eukaryotes

Question 20

Which of the following is the correct net equation for the complete oxidation of one molecule of glucose in aerobic respiration?

Accepted Answer

$$ 	ext{C}_6	ext{H}_{12}	ext{O}_6 + 6	ext{O}_2 ightarrow 6	ext{CO}_2 + 6	ext{H}_2	ext{O} + 	ext{energy} $$

Microbial Metabolism: Pathways of Energy Production and Catabolism

Study Guide - Practice Questions