Question 1

Which of the following best describes a catabolic pathway?

Accepted Answer

A pathway that releases energy by breaking down complex molecules into simpler compounds.

Question 2

Cellular respiration is an example of which type of metabolic pathway?

Accepted Answer

A catabolic pathway

Question 3

Which equation correctly represents the calculation of free energy change ($$\Delta G) in a $$system?

Accepted Answer

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

Question 4

A chemical reaction has reactants with $$G = 100$$ kcal/mol and products with $$G = 150$$ kcal/mol. Which statement is correct?

Accepted Answer

The reaction is non-spontaneous and endergonic.

Question 5

Which of the following statements about enzymes is TRUE?

Accepted Answer

Enzymes lower the activation energy ($$E_a) $$barrier, speeding up reactions.

Question 6

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

Accepted Answer

The synthesis of protein from amino acids.

Question 7

What is the main benefit of feedback inhibition in metabolic pathways?

Accepted Answer

It prevents the cell from wasting chemical resources by synthesizing more product than needed.

Question 8

Which of the following best describes the difference between kinetic and potential energy?

Accepted Answer

Kinetic energy is energy associated with motion, while potential energy is energy that matter possesses because of its location or structure.

Question 9

Which statement about exergonic and endergonic reactions is correct?

Accepted Answer

Endergonic reactions have a positive $$\Delta G$$ and are non-spontaneous.

Question 10

A competitive inhibitor affects enzyme activity by:

Accepted Answer

Binding to the active site and competing with the substrate.

Question 11

Which of the following is TRUE about allosteric regulation of enzymes?

Accepted Answer

Allosteric regulation can either inhibit or stimulate enzyme activity.

Question 12

Which of the following would most likely occur if a cell could not regulate its metabolic pathways?

Accepted Answer

Chemical chaos would result due to uncontrolled reactions.

Question 13

Which of the following is NOT a way that cells regulate enzyme activity?

Accepted Answer

Allowing all metabolic pathways to run simultaneously without control.

Question 14

Which of the following is TRUE regarding the relationship between free energy and stability in a system?

Accepted Answer

A system with less free energy ($$G) is $$more stable.

Question 15

Which of the following is a real-world example of energy conversion in living organisms?

Accepted Answer

A firefly converting chemical energy to light through bioluminescence.

Question 16

Which of the following statements about activation energy ($$E_a) is $$correct?

Accepted Answer

Activation energy is the initial energy needed to start a chemical reaction.

Question 17

Which of the following would most likely result from the inhibition of an early step in a metabolic pathway by its end product?

Accepted Answer

The pathway would be shut down, conserving resources.

Question 18

Which of the following is TRUE about the effect of temperature and pH on enzyme activity?

Accepted Answer

Each enzyme has an optimal temperature and pH at which it functions best.

Question 19

Which of the following is a correct statement about the role of enzymes in metabolic pathways?

Accepted Answer

Each step in a metabolic pathway is catalyzed by a specific enzyme.

The Energy of Life: Metabolism and Thermodynamics in Cells

Study Guide - Practice Questions