Q: A reaction has $\Delta G < 0$. What does this indicate about the reaction?

It is exergonic and spontaneous.

Q: Which of the following best describes how ATP powers cellular work?

ATP couples exergonic and endergonic reactions, allowing energy released from one to power the other.

Q: Which of the following is NOT a way that enzymes lower the activation energy ($E_a$) of a reaction?

Increasing the change in free energy ($\Delta G$) of the reaction.

Q: A competitive inhibitor affects enzyme activity by:

Binding to the active site and competing with the substrate.

Q: Which scenario best illustrates feedback inhibition in a metabolic pathway?

The end product of a pathway binds to an enzyme early in the pathway, inhibiting its activity.

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

A metabolic pathway consists of several steps, each catalyzed by a specific enzyme. What is the primary advantage of organizing metabolism into pathways?

Accepted Answer

It enables precise regulation and control of each step in the process.

Question 3

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

Accepted Answer

The chemical bonds in a glucose molecule.

Question 4

According to the Second Law of Thermodynamics, what happens during every energy transfer in biological systems?

Accepted Answer

The entropy of the universe increases.

Question 5

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

Accepted Answer

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

Question 6

A reaction has $\Delta G < 0$. What does this indicate about the reaction?

Accepted Answer

It is exergonic and spontaneous.

Question 7

Which of the following best describes how ATP powers cellular work?

Accepted Answer

ATP couples exergonic and endergonic reactions, allowing energy released from one to power the other.

Question 8

Which of the following is NOT a way that enzymes lower the activation energy ($E_a$) of a reaction?

Accepted Answer

Increasing the change in free energy ($\Delta G$) of the reaction.

Question 9

A competitive inhibitor affects enzyme activity by:

Accepted Answer

Binding to the active site and competing with the substrate.

Question 10

Which scenario best illustrates feedback inhibition in a metabolic pathway?

Accepted Answer

The end product of a pathway binds to an enzyme early in the pathway, inhibiting its activity.

Question 11

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

Accepted Answer

Photosynthesis converting light energy into chemical energy.

Question 12

If a cell needs to transport a solute against its concentration gradient, which type of work is being performed and what is the role of ATP?

Accepted Answer

Transport work; ATP provides energy for the process.

Question 13

Which of the following statements about enzymes is correct?

Accepted Answer

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

Question 14

A noncompetitive inhibitor affects enzyme activity by:

Accepted Answer

Binding to another part of the enzyme, changing its shape and reducing active site effectiveness.

Question 15

Which of the following best explains why energy conversions in cells are never 100% efficient?

Accepted Answer

Some energy is always lost as heat, increasing entropy.

Question 16

Which of the following is true about exergonic reactions?

Accepted Answer

They release free energy and occur spontaneously.

Question 17

Which of the following is NOT a form of energy relevant to biological systems?

Accepted Answer

Nuclear energy

Question 18

In a cell, which process is most likely to be endergonic?

Accepted Answer

Synthesis of proteins from amino acids

Question 19

Which of the following would increase the rate of an enzyme-catalyzed reaction?

Accepted Answer

Increasing substrate concentration (up to a point)

Question 20

Which of the following best describes allosteric regulation of enzymes?

Accepted Answer

A regulatory molecule binds to a site other than the active site, affecting enzyme function.

An Introduction to Metabolism (Chapter 8) – General Biology Study Notes

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