Question 1

Which of the following best describes the first law of thermodynamics as it applies to biological systems?

Accepted Answer

Energy can be transferred and transformed, but it cannot be created or destroyed.

Question 2

A metabolic pathway that breaks down glucose to generate ATP is an example of which type of pathway?

Accepted Answer

Catabolic pathway

Question 3

Which of the following statements about entropy is correct?

Accepted Answer

Entropy is a measure of molecular disorder and increases in every energy transfer or transformation.

Question 4

Given the equation for free energy change $$\Delta G = \Delta H - T\Delta S$$, which scenario would most likely result in a spontaneous reaction?

Accepted Answer

$$\Delta G is $$negative

Question 5

Which of the following is an example of potential energy in a biological context?

Accepted Answer

A glucose molecule with energy stored in its chemical bonds

Question 6

What is the primary role of ATP in cellular metabolism?

Accepted Answer

To couple exergonic and endergonic reactions, providing energy for cellular work

Question 7

Which of the following best explains why enzymes are necessary for metabolic reactions?

Accepted Answer

They lower the activation energy ($$E_A) $$required for reactions to proceed.

Question 8

A competitive inhibitor decreases the rate of an enzyme-catalyzed reaction by:

Accepted Answer

Binding to the active site, preventing substrate binding.

Question 9

Which of the following is true regarding the regeneration of ATP in cells?

Accepted Answer

ATP is regenerated by the addition of a phosphate group to ADP, using energy from catabolic reactions.

Question 10

Which of the following best describes the induced fit model of enzyme function?

Accepted Answer

The enzyme changes shape slightly to fit more snugly around the substrate, enhancing catalysis.

Question 11

A reaction has $$\Delta H = -50 kJ/$$mol, $$\Delta S = -0.1 kJ/($$mol·K), and occurs at $$T = 300 K. $$What is $$\Delta G$$ for this reaction, and is it spontaneous?

Accepted Answer

$$\Delta G = -20 kJ/$$mol; the reaction is spontaneous.

Question 12

Which of the following is NOT a function of ATP in the cell?

Accepted Answer

Acting as a coenzyme for all metabolic enzymes

Question 13

Which of the following statements about exergonic and endergonic reactions is correct?

Accepted Answer

Exergonic reactions release energy and have a negative $$\Delta G.$$

Question 14

Which of the following environmental changes would most likely decrease the rate of an enzyme-catalyzed reaction in the human body?

Accepted Answer

Decreasing the pH from 7.4 to 2 for an enzyme normally active in the blood

Question 15

Which of the following best explains why living organisms do not violate the second law of thermodynamics?

Accepted Answer

They increase the entropy of their surroundings through metabolic processes.

Question 16

A noncompetitive inhibitor decreases the rate of an enzyme-catalyzed reaction by:

Accepted Answer

Binding to a site other than the active site, causing a conformational change in the enzyme.

Question 17

Which of the following is an example of energy coupling in a cell?

Accepted Answer

The hydrolysis of ATP to drive the synthesis of glutamine from glutamic acid and ammonia.

Question 18

Which of the following best describes the role of cofactors in enzyme activity?

Accepted Answer

Cofactors are nonprotein helpers that may be inorganic ions or organic molecules required for enzyme function.

Question 19

A cell is synthesizing a polypeptide from amino acids. This process is best described as:

Accepted Answer

An anabolic pathway

An Introduction to Metabolism (Campbell Biology, Ch. 8): Study Notes

Study Guide - Practice Questions

Study Guide - Flashcards