Question 1

Which of the following best describes the first law of thermodynamics as it applies to biological systems?

Accepted Answer

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

Question 2

A cell uses ATP to power the active transport of ions across its membrane. Which best describes the role of ATP in this process?

Accepted Answer

ATP provides energy by transferring a phosphate group to a transport protein.

Question 3

Which of the following equations correctly represents the change in free energy ($$\Delta G) of a $$chemical reaction?

Accepted Answer

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

Question 4

Which scenario best illustrates the concept of potential energy in a biological context?

Accepted Answer

A molecule of glucose storing energy in its chemical bonds.

Question 5

In the context of metabolism, what is a metabolic pathway?

Accepted Answer

A series of enzyme-catalyzed reactions that transform a specific molecule into a final product.

Question 6

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

Accepted Answer

The synthesis of proteins from amino acids.

Question 7

A scientist measures the entropy ($$S) $$change in a reaction and finds it increases. According to the second law of thermodynamics, what does this imply about the reaction?

Accepted Answer

The reaction is spontaneous and increases disorder in the system.

Question 8

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

Accepted Answer

To maintain order and counteract the natural tendency toward increased entropy.

Question 9

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

Accepted Answer

The reaction is spontaneous and can perform work.

Question 10

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

Accepted Answer

Conversion of light energy to chemical energy during photosynthesis.

Question 11

A metabolic pathway is regulated by feedback inhibition. Which of the following best describes this process?

Accepted Answer

The final product of the pathway inhibits an enzyme that acts early in the pathway.

Question 12

Which of the following statements about catabolic pathways is correct?

Accepted Answer

Catabolic pathways release energy by breaking down complex molecules.

Question 13

During the process of bioluminescence in marine organisms, which type of energy transformation occurs?

Accepted Answer

Chemical energy is converted to light energy.

Question 14

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

Accepted Answer

Enzymes speed up reactions by lowering the activation energy.

Question 15

A cell is observed to have a high rate of ATP hydrolysis. Which of the following is most likely occurring in the cell?

Accepted Answer

The cell is performing a large amount of work, such as active transport or biosynthesis.

Question 16

Which of the following is true regarding the coupling of exergonic and endergonic reactions in cells?

Accepted Answer

Exergonic reactions provide the energy required to drive endergonic reactions.

Question 17

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

Accepted Answer

ATP can easily transfer a phosphate group to other molecules, releasing energy for cellular work.

Question 18

A reaction in a cell has $$\Delta H = -50 kJ/$$mol and $$\Delta S = -0.1 kJ/($$mol\cdot K). At $$T = 300 K$$, what is $$\Delta G$$ for the reaction?

Accepted Answer

$$\Delta G = -50 - (300 	imes -0.1) = -50 + 30 = -20 kJ/$$mol

Question 19

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

Accepted Answer

The movement of ions through a membrane channel.

Question 20

Which of the following statements about energy transformation in living organisms is correct?

Accepted Answer

Energy transformations increase the entropy of the universe.

Introduction to Metabolism and the Energy of Life

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