Question 1

Which of the following best describes metabolism in living organisms?

Accepted Answer

The total of all chemical reactions carried out by an organism, including both anabolic and catabolic pathways.

Question 2

A child climbs to the top of a slide and then slides down. Which type of energy does the child have at the top, and which type while sliding down?

Accepted Answer

Potential energy at the top; kinetic energy while sliding down.

Question 3

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

Accepted Answer

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

Question 4

Which of the following equations correctly represents the relationship between free energy ($$G$$), enthalpy ($$H$$), entropy ($$S$$), and temperature ($$T$$)?

Accepted Answer

$$G = H - TS$$

Question 5

In a redox reaction, which molecule gains energy?

Accepted Answer

The reduced molecule

Question 6

Which of the following reactions is exergonic?

Accepted Answer

A reaction with a negative $$\Delta G$$

Question 7

ATP is often called the 'energy currency' of the cell because:

Accepted Answer

Its hydrolysis releases energy that can drive endergonic reactions.

Question 8

Which molecule contains the most free energy?

Accepted Answer

Adenosine triphosphate (ATP)

Question 9

Which of the following best describes how enzymes speed up chemical reactions?

Accepted Answer

They lower the activation energy required for the reaction.

Question 10

A scientist is studying a reaction with $$\Delta G = +15 kJ/$$mol. Which of the following is true about this reaction?

Accepted Answer

It is endergonic and requires an input of energy.

Question 11

Which of the following factors can increase the effectiveness of an allosteric enzyme activator?

Accepted Answer

Increased concentrations of substrate

Question 12

Which of the following statements about feedback inhibition is correct?

Accepted Answer

The end product of a metabolic pathway inhibits an earlier enzyme in the pathway.

Question 13

A patient has an accumulation of an intermediate substrate in a metabolic pathway. Which is the most likely explanation?

Accepted Answer

A non-functioning enzyme later in the pathway is preventing further conversion.

Question 14

Which of the following is NOT a function of cofactors or coenzymes in enzymatic reactions?

Accepted Answer

They permanently alter the enzyme's primary structure.

Question 15

Which of the following best explains why ATP is not suitable for long-term energy storage?

Accepted Answer

Its phosphate bonds are unstable and it is rapidly hydrolyzed.

Question 16

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

Accepted Answer

Synthesis of proteins from amino acids

Question 17

Which of the following statements about enzyme specificity is correct?

Accepted Answer

Enzymes have active sites that are specific to their substrates due to their three-dimensional shape.

Question 18

A competitive inhibitor of an enzyme works by:

Accepted Answer

Binding to the active site and preventing substrate binding.

Question 19

Which of the following best describes the role of catabolic pathways in metabolism?

Accepted Answer

They break down complex molecules into simpler ones, releasing energy.

Question 20

If a reaction has $$\Delta H = -50 kJ/$$mol, $$T = 300 K$$, and $$\Delta S = +0.1 kJ/($$mol\cdot K), what is the value of $$\Delta G$$ and is the reaction spontaneous?

Accepted Answer

$$\Delta G = -80 kJ/$$mol; the reaction is spontaneous.

Metabolism, Energy, and Enzymes: Foundations of Cellular Function

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