Question 1

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

Accepted Answer

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

Question 2

During cellular respiration, glucose is broken down in the presence of oxygen. Which type of metabolic pathway does this process represent?

Accepted Answer

A catabolic pathway

Question 3

Which of the following best explains why living organisms do not violate the second law of thermodynamics?

Accepted Answer

Organisms increase order locally, but the total entropy of the system and surroundings increases.

Question 4

Which equation correctly relates the change in free energy ($$\Delta G) to $$enthalpy ($$\Delta H$$), entropy ($$\Delta S$$), and temperature ($$T$$)?

Accepted Answer

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

Question 5

A chemical reaction has $$\Delta G \u003c 0. $$What can be concluded about this reaction?

Accepted Answer

It is spontaneous and can perform work.

Question 6

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

Accepted Answer

The arrangement of electrons in the bonds of a glucose molecule

Question 7

Why does ATP have a high potential energy compared to most other molecules?

Accepted Answer

Because of the repulsion between the negative charges of its three phosphate groups

Question 8

Which process in cells is powered by the hydrolysis of ATP?

Accepted Answer

Pumping ions against their concentration gradient

Question 9

In a metabolic pathway, what is the role of enzymes?

Accepted Answer

They speed up specific reactions by lowering the activation energy.

Question 10

Which statement about exergonic and endergonic reactions is correct?

Accepted Answer

Endergonic reactions absorb free energy and have $$\Delta G \u003e 0.$$

Question 11

A cell is placed in a closed system where no energy or matter can enter or leave. What will eventually happen to the cell’s metabolic reactions?

Accepted Answer

They will reach equilibrium and no longer perform work.

Question 12

Which of the following best describes energy coupling in cells?

Accepted Answer

Using an exergonic process to drive an endergonic one

Question 13

What is the effect of feedback inhibition on a metabolic pathway?

Accepted Answer

It shuts down the pathway when the end product accumulates.

Question 14

Which of the following is an example of allosteric regulation?

Accepted Answer

A regulatory molecule binding to a site other than the active site, changing enzyme activity

Question 15

Which statement about the ATP cycle is correct?

Accepted Answer

ATP is regenerated from ADP by catabolic reactions that release energy.

Question 16

A scientist measures the free energy change ($$\Delta G) $$for a reaction and finds it to be positive. What does this indicate about the reaction?

Accepted Answer

The reaction is nonspontaneous and requires energy input.

Question 17

Which of the following scenarios illustrates the second law of thermodynamics in a biological context?

Accepted Answer

A cell breaks down glucose, releasing heat and small molecules, increasing entropy in the surroundings.

Question 18

Which of the following is true about metabolic pathways in living cells?

Accepted Answer

They are kept out of equilibrium by the constant flow of materials in and out of the cell.

Question 19

Which of the following best describes the role of compartmentalization in eukaryotic cells?

Accepted Answer

It brings order to metabolic pathways by localizing enzymes within specific organelles.

Chapter 8: An Introduction to Metabolism (Campbell Biology, 12th Edition)

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