Question 1

Which statement best describes the First Law of Thermodynamics as it applies to biological systems?

Accepted Answer

Energy can be transferred and transformed, but the total energy of the universe remains constant.

Question 2

A chemical reaction in a cell requires an input of energy and is not spontaneous. Which type of reaction is this?

Accepted Answer

Endergonic reaction

Question 3

Which of the following best illustrates the concept of activation energy in a chemical reaction?

Accepted Answer

The minimum amount of energy required for reactant molecules to reach the transition state and begin a reaction.

Question 4

In the context of metabolism, which pathway is responsible for breaking down complex molecules and releasing energy?

Accepted Answer

Catabolic pathway

Question 5

Which of the following is true about enzymes?

Accepted Answer

Enzymes lower the activation energy required for a reaction.

Question 6

A scientist is studying a reaction that releases energy and occurs spontaneously. What is the sign of $$\Delta G$$ for this reaction?

Accepted Answer

$$\Delta G \u003c 0$$

Question 7

Which of the following best describes the Second Law of Thermodynamics?

Accepted Answer

Every energy transfer increases the disorder (entropy) of the universe.

Question 8

Which statement about coupled reactions in cells is correct?

Accepted Answer

Energy released from an exergonic reaction can drive an endergonic reaction.

Question 9

A metabolic pathway that synthesizes proteins from amino acids is best described as:

Accepted Answer

Anabolic and endergonic

Question 10

Which of the following is NOT a property of a catalyst?

Accepted Answer

It is permanently changed by the reaction.

Question 11

Which of the following statements about chemical equilibrium is correct?

Accepted Answer

At equilibrium, the rates of the forward and reverse reactions are equal.

Question 12

Which of the following best describes the role of coenzymes in enzymatic reactions?

Accepted Answer

Coenzymes are small nonprotein organic molecules required for proper enzyme function.

Question 13

A competitive inhibitor affects enzyme activity by:

Accepted Answer

Binding to the active site and preventing substrate binding.

Question 14

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

Accepted Answer

Increasing substrate concentration up to a certain point.

Question 15

Which of the following is an example of potential energy in a biological system?

Accepted Answer

Energy stored in the chemical bonds of glucose.

Question 16

Which process is an example of kinetic energy in a cell?

Accepted Answer

The movement of motor proteins along microtubules.

Question 17

Which of the following statements about metabolic pathways is correct?

Accepted Answer

Anabolic pathways require energy to synthesize complex molecules.

Question 18

If a cell is placed in an environment where the temperature is much higher than the enzyme's optimum, what is the most likely outcome?

Accepted Answer

The enzyme may denature and lose its activity.

Question 19

Which of the following best explains why the planet Earth does not run out of energy?

Accepted Answer

Energy is constantly flowing in from the sun.

Question 20

A noncompetitive inhibitor affects enzyme activity by:

Accepted Answer

Binding to a site other than the active site, causing a change in enzyme shape.

Energy Flow in the Life of a Cell: Study Notes

Study Guide - Practice Questions