Question 1

Which of the following best describes the relationship between catabolism and anabolism in cellular metabolism?

Accepted Answer

Catabolism breaks down complex molecules to provide energy and building blocks for anabolism, which uses that energy to build complex molecules.

Question 2

A scientist is studying a metabolic pathway in which a phosphate group is directly transferred from a phosphorylated substrate to ADP, forming ATP. Which type of phosphorylation is being observed?

Accepted Answer

Substrate-level phosphorylation

Question 3

Which of the following statements about enzymes is TRUE?

Accepted Answer

Enzymes speed up chemical reactions by lowering the activation energy.

Question 4

A researcher adds a molecule to an enzyme-catalyzed reaction. The molecule binds to the enzyme's active site, preventing the substrate from binding. Which type of inhibition is this?

Accepted Answer

Competitive inhibition

Question 5

Which of the following best describes the role of ATP in metabolism?

Accepted Answer

ATP acts as an energy currency, transferring energy from catabolic to anabolic reactions.

Question 6

Which of the following is a correct sequence of events in the mechanism of enzymatic action?

Accepted Answer

Substrate binds to enzyme active site, forms enzyme-substrate complex, reaction occurs, products are released, enzyme is unchanged

Question 7

Which of the following factors does NOT directly affect the rate of enzymatic activity?

Accepted Answer

Oxygen concentration

Question 8

A laboratory test is performed to identify bacteria that can catabolize carbohydrates, resulting in acid production and a color change in the medium. Which test is being described?

Accepted Answer

Fermentation test

Question 9

Which of the following statements about the chemiosmotic model for ATP generation is correct?

Accepted Answer

ATP is generated as protons (H+) flow back through ATP synthase, using the energy from the proton gradient.

Question 10

During glycolysis, what are the net products formed from one molecule of glucose?

Accepted Answer

2 pyruvate, 2 ATP, 2 NADH, and water

Question 11

Which of the following is a correct description of a ribozyme?

Accepted Answer

An RNA molecule that acts as a catalyst, binding to substrates and facilitating reactions

Question 12

In the context of redox reactions, which of the following statements is correct?

Accepted Answer

Oxidation is the removal of electrons, and reduction is the gain of electrons.

Question 13

A bacterium is found to use nitrate ($$\mathrm{NO_3$^-}) as $$its final electron acceptor in respiration. Which type of respiration is this organism performing?

Accepted Answer

Anaerobic respiration

Question 14

Which of the following is a product of the Krebs cycle for each molecule of glucose?

Accepted Answer

$$4\ \mathrm{CO_2$}$$, $$6\ \mathrm{NADH}$$, $$2\ \mathrm{$$FADH_2$$}$$, $$2\ \mathrm{ATP}$$

Question 15

Which of the following best explains why fermentation produces less ATP than aerobic respiration?

Accepted Answer

Fermentation does not use the electron transport chain or oxygen as a final electron acceptor.

Question 16

Which of the following is a distinguishing feature of photoautotrophs?

Accepted Answer

They use light energy to fix $$\mathrm{CO_2$}$$ into organic molecules.

Question 17

A patient’s muscle cells are deprived of oxygen during intense exercise. Which metabolic pathway is most likely to be active in these cells, and what is the main product?

Accepted Answer

Lactic acid fermentation; lactic acid

Question 18

Which of the following statements about light-dependent and light-independent reactions in photosynthesis is correct?

Accepted Answer

Light-dependent reactions produce ATP and NADPH, while light-independent reactions use these molecules to synthesize organic compounds.

Question 19

Which of the following best describes a chemoheterotroph?

Accepted Answer

An organism that obtains both energy and carbon from organic compounds

Question 20

A bacterial culture is tested for the presence of cytochrome c oxidase. Which biochemical test is being performed, and what is its significance?

Accepted Answer

Oxidase test; identifies bacteria that possess cytochrome c oxidase

Chapter 5

Study Guide - Practice Questions

Study Guide - Flashcards