Q: Which statement correctly explains the role of ATP in coupling exergonic and endergonic reactions?

ATP hydrolysis provides energy from an exergonic reaction to drive an endergonic reaction

Q: Which of the following equations correctly represents the Gibbs free energy change for a chemical reaction?

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

Q: Which of the following statements about enzymes is TRUE?

Enzymes lower the activation energy, allowing reactions to proceed faster

Q: What is the primary reason ATP has high potential energy?

It contains clustered negative charges in its phosphate groups

Q: Which of the following best describes the induced fit model of enzyme action?

Substrates bind to the active site, causing the enzyme to change shape and facilitate the reaction

Question 1

Which of the following best describes an exergonic reaction in biological systems?

Accepted Answer

A reaction that releases energy, is spontaneous, and has $\Delta G < 0$

Question 2

Which statement correctly explains the role of ATP in coupling exergonic and endergonic reactions?

Accepted Answer

ATP hydrolysis provides energy from an exergonic reaction to drive an endergonic reaction

Question 3

Which of the following equations correctly represents the Gibbs free energy change for a chemical reaction?

Accepted Answer

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

Question 4

A bombadier beetle releases a hot chemical spray as a defense mechanism (as shown in the image). Which type of reaction is primarily responsible for the rapid release of energy in this process?

Accepted Answer

Exergonic reaction

Question 5

Which of the following statements about enzymes is TRUE?

Accepted Answer

Enzymes lower the activation energy, allowing reactions to proceed faster

Question 6

What is the primary reason ATP has high potential energy?

Accepted Answer

It contains clustered negative charges in its phosphate groups

Question 7

Which of the following best describes the induced fit model of enzyme action?

Accepted Answer

Substrates bind to the active site, causing the enzyme to change shape and facilitate the reaction

Question 8

A reaction has $\Delta H < 0$ and $\Delta S > 0$. What can be concluded about the spontaneity of this reaction at standard temperature?

Accepted Answer

The reaction is spontaneous because it releases heat and increases disorder

Question 9

Which of the following is NOT a way enzymes can be regulated in cells?

Accepted Answer

Permanent denaturation by heat

Question 10

In a metabolic pathway, what is the role of enzyme specificity?

Accepted Answer

Each enzyme catalyzes a specific reaction, ensuring proper sequence of metabolic steps

Question 11

Which of the following best explains why enzymes from different organisms function best at different temperatures?

Accepted Answer

Enzyme structure is adapted to the organism's environment, affecting optimal temperature

Question 12

Which of the following is a correct statement about activation energy ($E_a$) in enzyme-catalyzed reactions?

Accepted Answer

Enzymes lower $E_a$, making it easier for reactants to reach the transition state

Question 13

Which of the following is a real-world example of energy coupling in cells?

Accepted Answer

Using ATP hydrolysis to power muscle contraction

Question 14

Which of the following is TRUE about the entropy ($S$) change in a spontaneous reaction?

Accepted Answer

Entropy increases ($\Delta S > 0$) in spontaneous reactions

Question 15

Which of the following is a function of enzyme cofactors?

Accepted Answer

They assist enzymes by acting as electron carriers or stabilizing enzyme structure

Question 16

A scientist measures the rate of an enzyme-catalyzed reaction at different substrate concentrations. Which graph best describes the relationship between substrate concentration and reaction rate?

Accepted Answer

An initial linear increase followed by a plateau as the enzyme becomes saturated

Question 17

Which of the following statements about metabolic pathways is correct?

Accepted Answer

Metabolic pathways are sequences of reactions, each catalyzed by a different enzyme

Question 18

Which of the following best describes the effect of a competitive inhibitor on enzyme activity?

Accepted Answer

It binds to the active site, preventing substrate binding

Question 19

Which of the following is a consequence of the first law of thermodynamics in biological systems?

Accepted Answer

Energy is neither created nor destroyed, but can change forms

Question 20

Which of the following is most likely to occur if the transition state of a reaction is stabilized by an enzyme?

Accepted Answer

The activation energy ($E_a$) decreases, speeding up the reaction

Energy, Enzymes, and Metabolism: Study Notes for General Biology

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