Question 1

Which of the following best describes an anabolic pathway in metabolism?

Accepted Answer

A pathway that consumes energy to build complex molecules from simpler ones.

Question 2

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

Accepted Answer

Catabolic pathway

Question 3

According to the first law of thermodynamics, which of the following statements is true?

Accepted Answer

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

Question 4

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

Accepted Answer

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

Question 5

A reaction with a negative $$\Delta G is $$described as:

Accepted Answer

Exergonic and spontaneous

Question 6

Which of the following is NOT a form of kinetic energy?

Accepted Answer

Energy stored in chemical bonds

Question 7

Why do living organisms not violate the second law of thermodynamics?

Accepted Answer

Because they increase the entropy of their surroundings even as they maintain order internally.

Question 8

Which statement about enzymes is correct?

Accepted Answer

Enzymes lower the activation energy ($$E_a) of a $$reaction.

Question 9

What is the role of ATP hydrolysis in cellular metabolism?

Accepted Answer

It releases energy that can be used to drive endergonic reactions.

Question 10

Which of the following best describes a competitive inhibitor?

Accepted Answer

It binds to the active site of an enzyme, blocking substrate binding.

Question 11

A scientist is studying an enzyme that works best at pH 2. Where in the human body is this enzyme most likely found?

Accepted Answer

Stomach

Question 12

Which of the following scenarios illustrates energy coupling in a cell?

Accepted Answer

Using the energy released from ATP hydrolysis to power active transport of ions across a membrane.

Question 13

If a reaction has $$\Delta G = +5$$ kcal/mol, which of the following is true?

Accepted Answer

The reaction is endergonic and requires energy input.

Question 14

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

Accepted Answer

Energy stored in the bonds of glucose

Question 15

What happens to the activation energy ($$E_a) of a $$reaction when an enzyme is present?

Accepted Answer

$$E_a$$ decreases

Question 16

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

Accepted Answer

It can either inhibit or stimulate enzyme activity by binding to a site other than the active site.

Question 17

A metabolic pathway consists of three reactions, each catalyzed by a different enzyme. If enzyme 2 is inhibited, what is the most likely result?

Accepted Answer

The intermediate produced by reaction 1 will accumulate.

Question 18

Which of the following best explains why ATP is considered the 'energy currency' of the cell?

Accepted Answer

ATP hydrolysis releases energy that can be used to power many cellular processes.

Question 19

Which of the following is a consequence of the second law of thermodynamics in biological systems?

Accepted Answer

Every energy transformation increases the total entropy of the universe.

Question 20

A noncompetitive inhibitor affects enzyme activity by:

Accepted Answer

Binding to a site other than the active site, causing a conformational change that reduces enzyme activity.

Metabolism and Energy Transformations in Biology

Study Guide - Practice Questions