Question 1

Which of the following best describes the process shown in the first image (glucose + oxygen → carbon dioxide + water + ATP)?

Accepted Answer

A catabolic, exergonic reaction that releases energy for cellular work.

Question 2

According to the second law of thermodynamics, what happens to the entropy of the universe during the process of cellular respiration?

Accepted Answer

Entropy increases because energy is dispersed as heat during the reaction.

Question 3

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

Accepted Answer

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

Question 4

Which of the following statements about ATP hydrolysis is correct?

Accepted Answer

ATP hydrolysis is an exergonic reaction that releases energy to drive cellular work.

Question 5

A reaction has a $$\Delta G of +3.4 $$kcal/mol. If it is coupled to ATP hydrolysis ($$\Delta G = -7.3$$ kcal/mol), what is the net $$\Delta G$$ for the coupled reaction?

Accepted Answer

$$-3.9$$ kcal/mol

Question 6

Which of the following best explains why enzymes are necessary for many biological reactions?

Accepted Answer

Enzymes lower the activation energy barrier, allowing reactions to occur more rapidly.

Question 7

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

Accepted Answer

Binding to the active site and preventing substrate binding.

Question 8

Which of the following is an example of an anabolic, endergonic process in cells?

Accepted Answer

Photosynthesis

Question 9

If an enzyme is inhibited and adding more substrate does NOT increase the reaction rate, what type of inhibition is most likely occurring?

Accepted Answer

Noncompetitive inhibition

Question 10

Which of the following best describes the role of ATP in cellular metabolism?

Accepted Answer

ATP couples exergonic and endergonic reactions by providing energy through hydrolysis.

Question 11

Which of the following is true about the citric acid cycle (as shown in the third image)?

Accepted Answer

It is a catabolic pathway that generates ATP, NADH, and FADH2.

Question 12

Which of the following best illustrates the first law of thermodynamics in a biological system?

Accepted Answer

A bear eating a fish and converting the chemical energy into kinetic energy and heat.

Question 13

Which of the following statements about entropy is correct?

Accepted Answer

Entropy is a measure of disorder; energy dispersal increases entropy.

Question 14

Which of the following is an example of energy coupling in cells?

Accepted Answer

Using the energy released from ATP hydrolysis to drive the synthesis of glutamine from glutamic acid and ammonia.

Question 15

Which of the following best describes feedback inhibition in metabolic pathways?

Accepted Answer

The end product of a pathway inhibits an enzyme at the start of the pathway.

Question 16

Which of the following is a correct statement about the relationship between catabolism and anabolism?

Accepted Answer

Catabolism is to anabolism as exergonic is to endergonic.

Question 17

Which of the following metabolic processes can occur without a net influx of energy from another process?

Accepted Answer

C$$_6H$_{12}O$_6 + 6 O$_2$$ \rightarrow 6 CO$$_2 + 6 H$_2O$$

Question 18

Some bacteria are metabolically active in hot springs because:

Accepted Answer

Their enzymes have high optimal temperatures.

Question 19

Which of the following best explains why the hydrolysis of ATP is often coupled to endergonic reactions in cells?

Accepted Answer

The energy released from ATP hydrolysis ($$\Delta G  0.$$

Metabolism and Energy Transformations in Biological Systems (chpt. 8)

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