Question 1

Which of the following best describes an anabolic pathway in cellular metabolism?

Accepted Answer

A pathway that builds complex molecules from simpler ones, requiring an input of energy.

Question 2

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

Accepted Answer

Energy can be transformed from one form to another, but the total amount of energy in the universe remains constant.

Question 3

A boulder at the top of a hill possesses which type of energy?

Accepted Answer

Potential energy

Question 4

Given the following values for a reaction: $\Delta H = -40.0\ \mathrm{kJ}$, $\Delta S = -0.10\ \mathrm{kJ/K}$, and $T = 300\ \mathrm{K}$, what is the Gibbs free energy change ($\Delta G$)?

Question 5

Which of the following is true about exergonic reactions?

Accepted Answer

They release energy to the surroundings and have a negative $\Delta G$.

Question 6

ATP hydrolysis is often coupled to endergonic reactions in cells. What is the main reason for this?

Accepted Answer

ATP hydrolysis provides energy to drive reactions that would not occur spontaneously.

Question 7

Which statement best explains how enzymes speed up chemical reactions?

Accepted Answer

Enzymes lower the activation energy ($E_A$) required for the reaction to proceed.

Question 8

A competitive inhibitor affects enzyme activity by:

Accepted Answer

Binding to the active site and preventing substrate binding.

Question 9

Which of the following factors can affect the rate of an enzyme-catalyzed reaction?

Accepted Answer

Temperature, pH, and the presence of cofactors.

Question 10

If the change in enthalpy ($\Delta H$) for a reaction is $-50.0\ \mathrm{kJ}$, the change in entropy ($\Delta S$) is $-0.150\ \mathrm{kJ/K}$, and the temperature ($T$) is $300\ \mathrm{K}$, what is the value of $\Delta G$?

Accepted Answer

$\Delta G = -5.0\ \mathrm{kJ}$

Question 11

Which of the following best describes the role of ATP in cellular metabolism?

Accepted Answer

ATP provides energy for cellular work by transferring a phosphate group to other molecules.

Question 12

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

Accepted Answer

Gravitational energy

Question 13

What is the effect of increasing temperature beyond the optimal range for an enzyme?

Accepted Answer

The enzyme denatures and loses its catalytic activity.

Question 14

Which of the following statements about metabolic pathways is correct?

Accepted Answer

Metabolic pathways consist of a series of enzyme-catalyzed reactions.

Question 15

Which equation correctly represents the calculation of Gibbs free energy change ($\Delta G$)?

Accepted Answer

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

Question 16

Which of the following is a real-life example of energy transformation in biological systems?

Accepted Answer

A muscle contracting to lift a weight, converting chemical energy to kinetic energy.

Question 17

Which statement about enzyme specificity is correct?

Accepted Answer

Enzyme specificity is determined by the shape of the active site.

Question 18

Which of the following is true about the ATP cycle?

Accepted Answer

ATP is constantly regenerated from ADP and phosphate.

Question 19

Which of the following statements about activation energy ($E_A$) is correct?

Accepted Answer

Activation energy is the initial energy needed to break the bonds of reactants and start a chemical reaction.

Question 20

Which of the following is a function of cofactors in enzyme activity?

Accepted Answer

Cofactors are non-protein molecules that assist enzymes in catalysis.

Metabolism, Thermodynamics, and Enzyme Function in General Biology

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