Question 1

Which of the following best describes the relationship between catabolic and anabolic reactions in cellular metabolism?

Accepted Answer

Catabolic reactions provide energy and precursor molecules necessary for anabolic reactions.

Question 2

Which equation correctly represents the net reaction of glycolysis?

Accepted Answer

$$\mathrm{Glucose\ (C_6H_{12}O_6$) + 2\ NAD^+ + 2\ ADP + 2\ Pi \rightarrow 2\ Pyruvate\ (C_3H_4O_3) + 2\ NADH + 2\ ATP}$$

Question 3

A patient with a genetic disorder has a mutation that prevents the formation of NADH during glycolysis. Which of the following would most likely occur as a result?

Accepted Answer

Pyruvate would accumulate, but NAD+ would be depleted, halting glycolysis.

Question 4

Which of the following statements about ATP is TRUE?

Accepted Answer

ATP releases energy when its terminal phosphate bond is broken.

Question 5

Which of the following is an example of a competitive inhibitor affecting enzyme activity?

Accepted Answer

A molecule binds to the enzyme's active site, preventing substrate binding.

Question 6

Which of the following best explains why enzymes are essential for cellular life?

Accepted Answer

Enzymes allow reactions to proceed rapidly at physiological temperatures by lowering activation energy.

Question 7

Which of the following is NOT a correct description of a coenzyme?

Accepted Answer

Coenzymes are always composed of amino acids and function as protein catalysts.

Question 8

Which of the following best describes the process of chemiosmosis in cellular respiration?

Accepted Answer

ATP is produced as protons flow through ATP synthase, powered by a proton gradient across a membrane.

Question 9

Which of the following equations represents the products of one turn of the Krebs cycle for a single acetyl-CoA?

Accepted Answer

$$\mathrm{Acetyl{-}CoA + 3\ NAD^+ + FAD + ADP + Pi \rightarrow 2\ CO_2$ + 3\ NADH + $$FADH_2$$ + ATP + CoA}$$

Question 10

Which of the following is a key difference between aerobic and anaerobic respiration?

Accepted Answer

Aerobic respiration uses oxygen as the terminal electron acceptor, while anaerobic respiration uses other inorganic molecules.

Question 11

Which of the following best describes the role of NAD$$^+ in $$cellular metabolism?

Accepted Answer

NAD$$^+$$ acts as an electron carrier, accepting electrons during catabolic reactions and becoming NADH.

Question 12

Which of the following statements about ribozymes is TRUE?

Accepted Answer

Ribozymes are RNA molecules that can catalyze specific chemical reactions.

Question 13

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

Accepted Answer

ATP synthesis during glycolysis by direct transfer of a phosphate group from a phosphorylated intermediate to ADP.

Question 14

A bacterium is placed in an environment lacking oxygen but containing nitrate. Which metabolic pathway is most likely to be used for ATP production?

Accepted Answer

Anaerobic respiration, using nitrate as the final electron acceptor.

Question 15

Which of the following best describes the process of lactic acid fermentation?

Accepted Answer

Pyruvate is reduced by NADH to form lactate, regenerating NAD$$^+.$$

Question 16

Which of the following statements about the breakdown of lipids and proteins is TRUE?

Accepted Answer

Proteins are broken down into amino acids, which are deaminated and their carbon skeletons enter glycolysis or the Krebs cycle.

Question 17

Which of the following is NOT a factor that affects enzyme activity?

Accepted Answer

Genetic code sequence of the organism

Question 18

Which of the following best describes feedback inhibition in metabolic pathways?

Accepted Answer

The end product of a pathway binds to an enzyme early in the pathway, reducing its activity.

Question 19

Which of the following nutritional types describes an organism that uses light for energy and carbon dioxide as its carbon source?

Accepted Answer

Photoautotroph

Microbial Metabolism: Study Notes

Study Guide - Practice Questions

Study Guide - Flashcards