Question 1

Which of the following statements best describes the difference between exergonic and endergonic reactions in terms of Gibbs free energy ($$\Delta G$$)?

Accepted Answer

$$\Delta G is $$negative for exergonic reactions and positive for endergonic reactions.

Question 2

A researcher observes that a metabolic pathway is inhibited when the final product accumulates. What is this regulatory mechanism called?

Accepted Answer

Feedback inhibition

Question 3

Which of the following best explains why ATP has high potential energy?

Accepted Answer

It contains three phosphate groups with negative charges that repel each other.

Question 4

During a redox reaction, which molecule is reduced?

Accepted Answer

The molecule that gains electrons

Question 5

Which of the following is true regarding the effect of temperature on enzyme activity?

Accepted Answer

Each enzyme has an optimal temperature at which its activity is highest.

Question 6

A scientist adds a molecule that binds to the active site of an enzyme, preventing substrate binding. What type of regulation is this?

Accepted Answer

Competitive inhibition

Question 7

Which of the following best describes the role of enzymes in chemical reactions?

Accepted Answer

Enzymes decrease the activation energy, making reactions more likely to occur.

Question 8

Which of the following is a correct statement about catabolic pathways?

Accepted Answer

They break down large molecules into smaller ones and release energy.

Question 9

If a reaction has a negative change in enthalpy ($$\Delta H  0$$), what can be said about the spontaneity of the reaction at any temperature?

Accepted Answer

The reaction is always spontaneous.

Question 10

Which of the following best describes the process of energetic coupling in cells?

Accepted Answer

The use of energy from an exergonic reaction to drive an endergonic reaction.

Question 11

A patient with nonalcoholic fatty liver disease is found to have intestinal bacteria with increased anabolic activity. How might this contribute to obesity?

Accepted Answer

Anabolic activity in bacteria could increase the synthesis of energy-rich molecules, leading to greater energy absorption by the host.

Question 12

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

Accepted Answer

Increasing the number of peptide bonds in the substrate

Question 13

Which of the following statements about metabolic pathways is correct?

Accepted Answer

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

Question 14

Which of the following best explains why enzyme-catalyzed reactions show saturation kinetics?

Accepted Answer

At high substrate concentrations, all enzyme active sites are occupied, so the reaction rate plateaus.

Question 15

Which of the following is a correct description of the role of NADH in cellular metabolism?

Accepted Answer

NADH acts as an electron carrier, donating electrons to other molecules.

Question 16

Which of the following is true about the effect of pH on enzyme activity?

Accepted Answer

Each enzyme has an optimal pH at which its activity is highest.

Question 17

Which of the following is an example of a coenzyme?

Accepted Answer

NADH

Question 18

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

Accepted Answer

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

Question 19

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

Accepted Answer

The enzyme changes shape when the substrate binds, facilitating the reaction.

Question 20

Which of the following is a likely consequence if the active site of an enzyme is altered by mutation?

Accepted Answer

The enzyme may lose its ability to bind the substrate and catalyze the reaction.

Energy and Enzymes: An Introduction to Metabolism (Chapter 8 Study Notes)

Guida di studio - Domande di pratica

Study guide - Flashcard