Q: Which of the following is true for a reaction with $\Delta G < 0$?

The reaction is spontaneous and can perform work.

Q: Which of the following best explains why cells are considered open systems?

They constantly exchange energy and matter with their surroundings.

Q: ATP hydrolysis releases energy because:

The chemical change to a state of lower free energy releases energy.

Q: Which of the following is NOT a way that enzymes lower the activation energy ($E_A$) of a reaction?

Increasing the $\Delta G$ of the reaction

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

Binding to the active site and preventing substrate binding

Q: Which of the following best describes feedback inhibition in a metabolic pathway?

The end product of the pathway inhibits an enzyme that acts early in the pathway.

Q: Which of the following statements about allosteric regulation is correct?

Allosteric regulation involves binding of a regulatory molecule to a site other than the active site.

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 or transformed, but it cannot be created or destroyed.

Question 2

A metabolic pathway that synthesizes proteins from amino acids is an example of which type of pathway?

Accepted Answer

Anabolic pathway

Question 3

Which of the following statements about entropy is correct?

Accepted Answer

Every energy transfer or transformation increases the entropy of the universe.

Question 4

Which equation correctly represents the change in free energy ($\Delta G$) for a chemical reaction?

Accepted Answer

$\Delta G = G_{final} - G_{initial}$

Question 5

Which of the following is true for a reaction with $\Delta G < 0$?

Accepted Answer

The reaction is spontaneous and can perform work.

Question 6

Cellular respiration is an example of which type of reaction?

Accepted Answer

Exergonic reaction

Question 7

Which of the following best explains why cells are considered open systems?

Accepted Answer

They constantly exchange energy and matter with their surroundings.

Question 8

ATP hydrolysis releases energy because:

Accepted Answer

The chemical change to a state of lower free energy releases energy.

Question 9

Which of the following is NOT a way that enzymes lower the activation energy ($E_A$) of a reaction?

Accepted Answer

Increasing the $\Delta G$ of the reaction

Question 10

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

Accepted Answer

Binding to the active site and preventing substrate binding

Question 11

Which of the following best describes feedback inhibition in a metabolic pathway?

Accepted Answer

The end product of the pathway inhibits an enzyme that acts early in the pathway.

Question 12

Which of the following statements about allosteric regulation is correct?

Accepted Answer

Allosteric regulation involves binding of a regulatory molecule to a site other than the active site.

Question 13

Which of the following is a real-life example of energy coupling in cells?

Accepted Answer

The use of ATP hydrolysis to drive the active transport of sodium ions across a membrane

Question 14

Which of the following best explains why enzymes are specific for their substrates?

Accepted Answer

The active site of the enzyme has a unique shape that fits only specific substrates.

Question 15

A patient is given a drug that acts as a noncompetitive inhibitor of an essential enzyme. What is the most likely effect on the enzyme's activity?

Accepted Answer

The enzyme's active site will change shape, reducing its ability to catalyze the reaction.

Question 16

Which of the following is true about 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 17

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

Accepted Answer

Cofactors are nonprotein molecules that help enzymes catalyze reactions.

Question 18

A mutation changes the amino acid sequence of an enzyme's active site. Which of the following is the most likely consequence?

Accepted Answer

The enzyme may lose its specificity and catalytic activity.

Question 19

Which of the following scenarios best illustrates the second law of thermodynamics in a biological context?

Accepted Answer

A bear eats a fish, converting chemical energy in food to kinetic energy and releasing heat.

Question 20

Which of the following statements about metabolic equilibrium in cells is correct?

Accepted Answer

Cells are open systems and never reach metabolic equilibrium.

Chapter 6: An Introduction to Metabolism – Study Notes

Study Guide - Practice Questions

Study Guide - Flashcards