Question 1

Which of the following best describes metabolism in a living organism?

Accepted Answer

The sum of all chemical reactions occurring within the organism.

Question 2

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

Accepted Answer

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

Question 3

A diver climbs to the top of a platform and then jumps into the water. Which of the following best describes the energy transformations that occur?

Accepted Answer

Potential energy is converted to kinetic energy as the diver falls.

Question 4

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 5

Which of the following statements about exergonic reactions is TRUE?

Accepted Answer

They have a negative $$\Delta G$$ and occur spontaneously.

Question 6

Why are living cells considered open systems with respect to metabolism?

Accepted Answer

They experience a constant flow of materials and energy with their surroundings.

Question 7

ATP is often called the 'energy currency' of the cell. Which of the following best explains how ATP drives endergonic reactions?

Accepted Answer

By transferring a phosphate group to a reactant, making it more reactive (phosphorylation).

Question 8

Which of the following is NOT a function of enzymes in biological systems?

Accepted Answer

Increasing the activation energy required for a reaction.

Question 9

A patient is given a drug that acts as a competitive inhibitor for a key metabolic enzyme. Which of the following best describes how this drug works?

Accepted Answer

It binds to the active site of the enzyme, preventing the substrate from binding.

Question 10

Which of the following environmental factors can affect enzyme activity in the human body?

Accepted Answer

Both temperature and pH.

Question 11

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

Accepted Answer

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

Question 12

Which of the following statements about allosteric regulation of enzymes is correct?

Accepted Answer

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

Question 13

Which of the following best explains why cells must maintain metabolic pathways far from equilibrium?

Accepted Answer

To allow a constant flow of materials and energy, enabling work to be performed.

Question 14

A mutation changes an amino acid in the active site of an enzyme. What is the most likely consequence?

Accepted Answer

The enzyme's substrate specificity may be altered.

Question 15

Which of the following is an example of energy coupling in a cell?

Accepted Answer

Using the energy released from ATP hydrolysis to drive the active transport of ions across a membrane.

Question 16

Which of the following best describes the role of cofactors in enzyme activity?

Accepted Answer

They are nonprotein helpers that are required for some enzymes to function.

Question 17

A scientist measures the $$\Delta G of a $$reaction and finds it to be positive. What does this indicate about the reaction?

Accepted Answer

The reaction is endergonic and requires an input of energy to proceed.

Question 18

Which of the following is a real-world example of an enzyme inhibitor used in medicine?

Accepted Answer

Antibiotics that inhibit bacterial enzymes.

Question 19

Which of the following statements about the second law of thermodynamics is correct?

Accepted Answer

Every energy transfer or transformation increases the entropy of the universe.

Question 20

A cell is exposed to a toxin that irreversibly binds to the active site of a key enzyme. What is the most likely effect on the cell's metabolism?

Accepted Answer

The metabolic pathway involving that enzyme will be blocked, potentially leading to cell death.

Chapter 8: Metabolism – Study Notes for General Biology I

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