Question 1

Which of the following best describes the difference between kinetic and potential energy, as illustrated by a child on a slide?

Accepted Answer

Kinetic energy is the energy of motion, as when the child is sliding down, while potential energy is stored energy due to position, as when the child is at the top of the slide.

Question 2

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

Accepted Answer

Energy can be transformed from one form to another, but cannot be created or destroyed.

Question 3

A chemical reaction has a $$\Delta G ($$change in free energy) of $$-15 kJ/$$mol. Which of the following is true about this reaction?

Accepted Answer

It is exergonic and releases energy.

Question 4

Which of the following best explains how ATP hydrolysis powers endergonic reactions in cells?

Accepted Answer

The energy released from ATP hydrolysis is coupled to endergonic reactions, making the overall process exergonic.

Question 5

Which of the following is an example of a redox reaction in biological systems?

Accepted Answer

The transfer of electrons from NADH to the electron transport chain.

Question 6

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

Accepted Answer

Enzymes lower the activation energy, speeding up the rate of reaction without being consumed.

Question 7

A patient has a fever of 41°C (105.8°F). Which of the following best explains why some of their enzymes may not function properly at this temperature?

Accepted Answer

The enzymes are likely to be denatured, losing their specific three-dimensional structure required for activity.

Question 8

Which of the following statements about competitive and noncompetitive enzyme inhibition is correct?

Accepted Answer

Competitive inhibitors compete with the substrate for the active site, while noncompetitive inhibitors bind elsewhere and change the enzyme's shape.

Question 9

Which of the following best describes feedback inhibition in metabolic pathways?

Accepted Answer

The end product of a pathway acts as an allosteric inhibitor of an enzyme earlier in the pathway.

Question 10

Which of the following reactions is an example of an anabolic process?

Accepted Answer

$$\mathrm{ADP + P_i + energy \rightarrow ATP}$$

Question 11

A scientist measures the entropy ($$S) of a $$system before and after a chemical reaction. According to the second law of thermodynamics, which of the following is most likely true?

Accepted Answer

The total entropy of the system and its surroundings increases.

Question 12

Which of the following best explains why cells require a constant input of energy?

Accepted Answer

To maintain order and counteract the tendency toward increased entropy.

Question 13

Which of the following statements about metabolism is correct?

Accepted Answer

Catabolism refers to the breakdown of molecules to release energy, while anabolism refers to the synthesis of molecules using energy.

Question 14

Which of the following best describes the relationship between electron energy levels and redox reactions?

Accepted Answer

Oxidation is the loss of electrons (often from higher energy levels), and reduction is the gain of electrons (often to higher energy levels).

Question 15

A reaction has a high activation energy barrier. Which of the following is most likely to increase the rate of this reaction in a biological system?

Accepted Answer

Adding a specific enzyme to lower the activation energy.

Question 16

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

Accepted Answer

The active site of the enzyme has a specific shape that only fits certain substrates.

Question 17

In the context of homeostasis, why is it important for proteins (including enzymes) to maintain their proper structure?

Accepted Answer

Proper structure ensures that enzymes can bind to their substrates and catalyze reactions efficiently.

Question 18

Which of the following scenarios best illustrates the concept of coupling exergonic and endergonic reactions in a living cell?

Accepted Answer

The hydrolysis of ATP (exergonic) is used to drive the synthesis of glucose-6-phosphate from glucose and phosphate (endergonic).

Question 19

Which of the following best describes an exergonic reaction?

Accepted Answer

A reaction that releases energy and has a negative $$\Delta G.$$

Energy and Metabolism: Study Notes for General Biology

Study Guide - Practice Questions

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