Question 1

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

Accepted Answer

Catabolic pathways release energy by breaking down complex molecules, while anabolic pathways consume energy to build complex molecules.

Question 2

Which statement correctly explains why an organism is considered an open system?

Accepted Answer

It exchanges both energy and matter with its surroundings.

Question 3

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

Accepted Answer

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

Question 4

Which equation correctly represents the change in free energy for a reaction?

Accepted Answer

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

Question 5

A reaction has a $$\Delta G of -5.6 $$kcal/mol. Which of the following statements is true about this reaction?

Accepted Answer

The reaction is exergonic and spontaneous.

Question 6

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

Accepted Answer

ATP hydrolysis is coupled to endergonic reactions, making the overall process exergonic.

Question 7

Which of the following is NOT a component of ATP?

Accepted Answer

Deoxyribose

Question 8

Why is an investment of activation energy necessary to initiate a spontaneous reaction?

Accepted Answer

To destabilize existing bonds in the reactants so they can break and new bonds can form.

Question 9

Which of the following statements about enzymes is correct?

Accepted Answer

Enzymes lower the activation energy barrier, speeding up the reaction.

Question 10

A competitive inhibitor decreases the rate of an enzyme-catalyzed reaction by:

Accepted Answer

Binding to the active site and blocking substrate entry.

Question 11

Which of the following environmental factors can affect enzyme activity?

Accepted Answer

All of the above

Question 12

What is the effect of increasing substrate concentration on the rate of an enzyme-catalyzed reaction when the enzyme is saturated?

Accepted Answer

The reaction rate remains constant.

Question 13

Which of the following best describes allosteric regulation of an enzyme?

Accepted Answer

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

Question 14

How does feedback inhibition benefit a cell?

Accepted Answer

It prevents the cell from wasting chemical resources by stopping the pathway when enough product is made.

Question 15

Which of the following is an example of a process that increases entropy, according to the second law of thermodynamics?

Accepted Answer

Diffusion of a solute across a membrane.

Question 16

Which of the following statements about exergonic and endergonic reactions is correct?

Accepted Answer

Exergonic reactions have a negative $$\Delta G$$ and occur spontaneously.

Question 17

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

Accepted Answer

ATP couples energy released from catabolic reactions to power anabolic reactions.

Question 18

Which of the following is true about the induced-fit model of enzyme function?

Accepted Answer

The enzyme changes shape slightly to fit the substrate more snugly.

Question 19

A patient has a genetic mutation that causes their enzymes to denature at 37°C. Which of the following is the most likely consequence?

Accepted Answer

Their metabolic reactions will proceed much more slowly or not at all at normal body temperature.

Question 20

Which of the following statements about cofactors is correct?

Accepted Answer

Cofactors can be inorganic ions or organic molecules called coenzymes.

Chapter 8: An Introduction to Metabolism – General Biology Study Notes

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