Question 1

Which of the following best describes the First Law of Thermodynamics as it applies to biological systems?

Accepted Answer

Energy can be transformed from one form to another, but cannot be created or destroyed.

Question 2

A diver climbs to the top of a platform, then jumps into the water. Which statement best explains the energy transformations involved?

Accepted Answer

The diver's potential energy is highest on the platform and is converted to kinetic energy as they fall.

Question 3

Which of the following reactions is most likely to have a negative $$\Delta G$$ value?

Accepted Answer

The breakdown of glucose to carbon dioxide and water.

Question 4

According to the Second Law of Thermodynamics, what happens to the total entropy of the universe during a chemical reaction in a cell?

Accepted Answer

It increases because some energy is lost as heat, increasing disorder.

Question 5

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

Accepted Answer

ATP acts as an energy currency, coupling exergonic and endergonic reactions.

Question 6

A cell uses the energy from ATP hydrolysis to drive the synthesis of a macromolecule. What is the net $$\Delta G of $$the coupled reaction?

Accepted Answer

Negative, because the energy released from ATP hydrolysis exceeds the energy required for synthesis.

Question 7

Which of the following statements about enzymes is correct?

Accepted Answer

Enzymes lower the activation energy but do not change the $$\Delta G.$$

Question 8

In the context of redox reactions, which statement is true?

Accepted Answer

Reduction is the gain of electrons and is energetically unfavorable.

Question 9

Which of the following best illustrates the Second Law of Thermodynamics in a biological system?

Accepted Answer

A moose eating a plant and releasing heat as it moves.

Question 10

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

Accepted Answer

The concentration gradient of protons across a mitochondrial membrane.

Question 11

If a reaction has $$\Delta G \u003c 0$$, which of the following is true?

Accepted Answer

The reaction is exergonic and releases energy.

Question 12

Which of the following best explains why ATP hydrolysis releases a large amount of energy?

Accepted Answer

The electrostatic repulsion between phosphate groups makes the bonds unstable and easy to break.

Question 13

Which of the following scenarios represents an anabolic pathway?

Accepted Answer

The synthesis of DNA from nucleotides.

Question 14

A cell maintains a high concentration of potassium ions inside and a low concentration outside. What type of energy does this represent?

Accepted Answer

Potential energy

Question 15

Which of the following is true about the relationship between catabolic and anabolic reactions?

Accepted Answer

Catabolic reactions release energy, which can be used to drive anabolic reactions.

Question 16

Which of the following best describes the function of ATP synthase in mitochondria?

Accepted Answer

It harnesses the flow of protons down their concentration gradient to synthesize ATP from ADP and phosphate.

Question 17

Which of the following is a correct statement about enzyme inhibition?

Accepted Answer

Competitive inhibitors bind to the active site, blocking substrate binding.

Question 18

Which of the following best explains why cells require a constant input of energy?

Accepted Answer

To build and maintain order, counteracting the tendency toward increased entropy.

Question 19

Which of the following is an example of an exergonic reaction in a cell?

Accepted Answer

The hydrolysis of ATP to ADP and phosphate.

Question 20

Which of the following best describes the relationship between free energy ($$G$$), stability, and work capacity?

Accepted Answer

Lower free energy means greater stability and less work capacity.

Energy and Metabolism: Laws of Thermodynamics, Gibbs Free Energy, and Cellular Processes

스터디 가이드 - 연습 문제