Q: Which of the following reactions is exergonic?

$$ \Delta G = -7.3 \, \text{kcal/mol} $$

Q: A reaction has $$ \Delta G = +4.5 \, \text{kcal/mol} . $$Can this reaction be coupled to ATP hydrolysis ($$ \Delta G = -7.3 \, \text{kcal/mol} ) to $$proceed spontaneously? What is the net $$ \Delta G $$?

Yes; net $$ \Delta G = -2.8 \, \text{kcal/mol} $$

Question 1

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

Accepted Answer

Catabolic pathways break down complex molecules and release energy, while anabolic pathways build complex molecules and require energy.

Question 2

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

Accepted Answer

Glucose stored in a plant cell

Question 3

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

Accepted Answer

Energy is transferred and transformed, but the total amount remains constant.

Question 4

A bear eats a fish and uses the energy to run. This scenario best demonstrates which law of thermodynamics?

Accepted Answer

The first law, because energy is transformed from chemical to kinetic energy.

Question 5

Which of the following reactions is exergonic?

Accepted Answer

$$ \Delta G = -7.3 \, 	ext{kcal/mol} $$

Question 6

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

Accepted Answer

They lower the activation energy ($$ E_a ) $$required for the reaction.

Question 7

Which of the following statements about entropy ($$ S ) in $$biological systems is correct?

Accepted Answer

Living systems increase the entropy of their surroundings more than they decrease their own internal entropy.

Question 8

Which of the following best describes a spontaneous process in terms of free energy?

Accepted Answer

It releases free energy and $$ \Delta G \u003c 0 .$$

Question 9

During cellular respiration, glucose is broken down into carbon dioxide and water. Which type of metabolic pathway is this?

Accepted Answer

Catabolic pathway

Question 10

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

Accepted Answer

The energy released by ATP hydrolysis ($$ \Delta G = -7.3 \, 	ext{kcal/mol} ) $$can drive reactions with $$ \Delta G $$ less than or equal to $$ +7.3 \, 	ext{kcal/mol} .$$

Question 11

A reaction has $$ \Delta G = +4.5 \, 	ext{kcal/mol} . $$Can this reaction be coupled to ATP hydrolysis ($$ \Delta G = -7.3 \, 	ext{kcal/mol} ) to $$proceed spontaneously? What is the net $$ \Delta G $$?

Accepted Answer

Yes; net $$ \Delta G = -2.8 \, 	ext{kcal/mol} $$

Question 12

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

Accepted Answer

Chemical energy stored in glucose

Question 13

Which of the following best describes the role of enzymes in metabolic pathways?

Accepted Answer

They lower the activation energy ($$ E_a ) $$and speed up reactions.

Question 14

Which of the following scenarios would result in an increase in entropy ($$ S $$)?

Accepted Answer

Glucose is broken down into carbon dioxide and water.

Question 15

Why do living systems require a constant input of energy?

Accepted Answer

To maintain order and power cellular processes, as energy input must exceed energy loss.

Question 16

Which of the following best describes the change in free energy ($$ \Delta G ) $$for a spontaneous process?

Accepted Answer

$$ \Delta G  is $$negative and energy is released.

Question 17

Which of the following is a real-life example of an exergonic reaction?

Accepted Answer

Cellular respiration in animals

Question 18

If a cell is at equilibrium, which of the following statements is true?

Accepted Answer

There is no net change in free energy ($$ \Delta G = 0 ).$$

Question 19

Which of the following best explains why water held behind a dam has more free energy than water in a pond?

Accepted Answer

Water behind a dam has more potential energy due to its position.

Unit 3: Free Energy & Metabolism – Cellular Energetics Study Notes

Study Guide - Practice Questions

Study Guide - Flashcards