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, while anabolic pathways consume energy to build complex molecules.

Question 2

A bear eats a fish and then runs, as shown in the images. Which law of thermodynamics is demonstrated when the bear converts chemical energy from food into kinetic energy and heat?

Accepted Answer

Both the first and second laws of thermodynamics are demonstrated.

Question 3

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

Accepted Answer

$$\Delta G = \Delta H - T\Delta S$$

Question 4

A reaction has a $$\Delta G of -5.6 $$kcal/mol. Which of the following statements is true about this reaction?

Accepted Answer

The reaction is exergonic and spontaneous.

Question 5

Which of the following best explains why an organism is considered an open system?

Accepted Answer

It exchanges both energy and matter with its surroundings.

Question 6

Which of the following statements about ATP is correct?

Accepted Answer

ATP consists of adenine, ribose, and three phosphate groups.

Question 7

How does ATP typically power endergonic reactions in the cell?

Accepted Answer

By transferring a phosphate group to a reactant, making it more reactive.

Question 8

Which of the following is true regarding enzyme function?

Accepted Answer

Enzymes lower the activation energy ($$E_A) $$required for a reaction.

Question 9

A scientist increases the substrate concentration in an enzyme-catalyzed reaction, but the reaction rate no longer increases. What is the most likely explanation?

Accepted Answer

The enzyme is saturated; all active sites are occupied.

Question 10

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

Accepted Answer

The enzyme changes shape slightly to fit the substrate more closely upon binding.

Question 11

Which of the following environmental factors can affect enzyme activity?

Accepted Answer

Both temperature and pH, as well as cofactors and inhibitors.

Question 12

A patient is given a drug that binds to the active site of an enzyme, preventing the substrate from binding. What type of inhibition is this?

Accepted Answer

Competitive inhibition.

Question 13

Which of the following statements about feedback inhibition is correct?

Accepted Answer

Feedback inhibition prevents a cell from wasting resources by shutting down a metabolic pathway when the end product accumulates.

Question 14

Which of the following is an example of an anabolic pathway?

Accepted Answer

The synthesis of proteins from amino acids.

Question 15

Which of the following best explains why increasing temperature beyond an enzyme's optimal range decreases its activity?

Accepted Answer

The enzyme denatures, losing its specific three-dimensional structure.

Question 16

A metabolic pathway consists of several steps, each catalyzed by a different enzyme. If enzyme 2 is inhibited, what will happen to the concentrations of molecules A, B, C, and D in the pathway: A --(Enzyme 1)--\u003e B --(Enzyme 2)--\u003e C --(Enzyme 3)--\u003e D?

Accepted Answer

A and B will accumulate; C and D will decrease.

Question 17

Which of the following is true about the relationship between free energy, stability, and equilibrium in a system?

Accepted Answer

A spontaneous process decreases free energy and increases stability.

Question 18

Which of the following best describes the role of allosteric regulation in enzyme activity?

Accepted Answer

A molecule binds to a site other than the active site, causing a conformational change that affects enzyme activity.

Question 19

Which of the following statements about the ATP cycle is correct?

Accepted Answer

ATP is regenerated from ADP and inorganic phosphate using energy from catabolic (exergonic) reactions.

Question 20

A cell is exposed to a noncompetitive inhibitor. Which of the following is most likely to occur?

Accepted Answer

The inhibitor binds to a different site, causing the enzyme to change shape and reducing its activity.

Chapter 8: An Introduction to Metabolism – General Biology Study Notes

Guida di studio - Domande di pratica

Study guide - Flashcard