Question 1

Which of the following best describes the difference between catabolic and anabolic pathways in cellular metabolism?

Accepted Answer

Catabolic pathways release energy by breaking down complex molecules into simpler ones, while anabolic pathways consume energy to build complex molecules from smaller molecules.

Question 2

A scientist observes a reaction in which the products have more free energy than the reactants. Which of the following terms best describes this reaction?

Accepted Answer

Endergonic

Question 3

Which of the following statements about the second law of thermodynamics is correct as it applies to living organisms?

Accepted Answer

Living organisms increase the entropy of the universe by exchanging energy and matter with their surroundings.

Question 4

Which of the following best explains how ATP performs cellular work?

Accepted Answer

ATP hydrolysis releases a significant amount of energy that can be used to drive endergonic reactions.

Question 5

Enzymes lower the activation energy of a reaction by which of the following mechanisms?

Accepted Answer

Providing an active site or induced fit that stabilizes the transition state.

Question 6

Which of the following reactions is characterized by a negative change in free energy ($$\Delta G \u003c 0$$)?

Accepted Answer

Exergonic reactions

Question 7

A student adds a molecule to an enzyme solution that binds to the enzyme's active site, preventing substrate binding. What type of inhibition is this?

Accepted Answer

Competitive inhibition

Question 8

Which of the following best describes an induced fit in enzyme activity?

Accepted Answer

The enzyme changes shape slightly to fit the substrate more closely when the substrate binds.

Question 9

Which of the following is NOT a function of enzymes?

Accepted Answer

Increasing the overall free energy change ($$\Delta G) of a $$reaction

Question 10

What happens to an enzyme when it is denatured?

Accepted Answer

Its tertiary and quaternary structures are altered, causing loss of function.

Question 11

Which of the following statements about allosteric regulation is correct?

Accepted Answer

Allosteric activators can turn an enzyme on by binding to a site other than the active site.

Question 12

Which of the following best describes a ribozyme?

Accepted Answer

A biological catalyst made of RNA.

Question 13

A patient is given a drug that binds to an enzyme at a site other than the active site, causing the enzyme's active site to change shape and lose function. This is an example of:

Accepted Answer

Noncompetitive inhibition

Question 14

Which of the following best describes potential energy in a biological context?

Accepted Answer

Energy stored due to the location or structure of molecules.

Question 15

Which of the following is a correct statement about anabolic enzymes?

Accepted Answer

They catalyze reactions that build complex molecules from simpler ones.

Question 16

A metabolic pathway in a cell is switched off by the binding of its end product to an enzyme early in the pathway. This is an example of:

Accepted Answer

Feedback inhibition

Question 17

Which of the following scenarios would most likely result in enzyme denaturation?

Accepted Answer

A drastic change in pH or temperature.

Question 18

Which of the following is true regarding exergonic reactions?

Accepted Answer

They release energy and have a negative $$\Delta G.$$

Question 19

A researcher discovers a new enzyme that aligns two substrates in the correct orientation and provides a microenvironment favorable for bond formation. Which enzyme function is being described?

Accepted Answer

Aligning substrates and providing a favorable microenvironment

Question 20

Which of the following best explains why enzymes are considered catalysts?

Accepted Answer

They lower the activation energy without being permanently changed.

Enzymes and Metabolic Pathways: Study Notes for General Biology

Guida di studio - Domande di pratica

Study guide - Flashcard