Question 1

Which of the following best describes the role of activation energy in a chemical reaction?

Accepted Answer

It is the energy required to reach the transition state of a reaction.

Question 2

According to the equation $$\Delta G = \Delta H - T \Delta S$$, which condition will make a reaction spontaneous?

Accepted Answer

A negative $$\Delta G$$ value.

Question 3

Which statement about enzymes is correct?

Accepted Answer

Enzymes lower the activation energy, speeding up the reaction.

Question 4

A metabolic pathway involves several enzymes working in sequence. If the final product inhibits the activity of the first enzyme, this is an example of:

Accepted Answer

Feedback inhibition

Question 5

Which of the following is an example of an exergonic reaction?

Accepted Answer

A reaction with $$\Delta G \u003c 0$$ that releases energy.

Question 6

Which of the following best describes the function of a coenzyme?

Accepted Answer

A small organic molecule required for an enzyme-catalyzed reaction.

Question 7

If a reaction has a positive $$\Delta G$$, which of the following is true?

Accepted Answer

The reaction is endergonic and requires input of energy.

Question 8

Which of the following statements about redox reactions is correct?

Accepted Answer

Oxidation is the loss of electrons, and reduction is the gain of electrons.

Question 9

A competitive inhibitor affects enzyme activity by:

Accepted Answer

Binding to the active site and preventing substrate access.

Question 10

Which factor would most likely increase the rate of a chemical reaction in a biological system?

Accepted Answer

Increasing the concentration of reactants.

Question 11

Which of the following is true about metabolic pathways?

Accepted Answer

They involve a series of enzymes that modify substrates in sequence.

Question 12

Which molecule acts as an electron carrier in the citric acid cycle and is reduced during redox reactions?

Accepted Answer

FAD

Question 13

If the entropy ($$S) of a $$system increases, what is the likely effect on the free energy change ($$\Delta G) of a $$reaction at constant enthalpy ($$\Delta H) $$and temperature ($$T$$)?

Accepted Answer

$$\Delta G$$ will decrease.

Question 14

Which of the following best explains why enzymes are highly specific for their substrates?

Accepted Answer

The shape and chemical properties of the active site match the substrate.

Question 15

Which process is described by the addition of a phosphate group to a molecule?

Accepted Answer

Phosphorylation

Question 16

A reaction in which the product of one enzyme-catalyzed step serves as the substrate for the next enzyme in a pathway is an example of:

Accepted Answer

Metabolic pathway teamwork

Question 17

Which of the following is a correct statement about endergonic reactions?

Accepted Answer

They have $$\Delta G \u003e 0$$ and require input of energy.

Question 18

Which of the following is most likely to regulate enzyme activity by altering the primary structure of the enzyme?

Accepted Answer

Protein cleavage

Question 19

Which of the following is true about the transition state in an enzyme-catalyzed reaction?

Accepted Answer

It is a high-energy intermediate that must be achieved for the reaction to proceed.

Question 20

Which of the following would most likely decrease the rate of an enzyme-catalyzed reaction?

Accepted Answer

Decreasing temperature below the enzyme's optimal range.

Energy, Enzymes, and Metabolic Pathways: General Biology Study Notes

Guida di studio - Domande di pratica

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