Question 1

Which of the following best describes the difference between kinetic and potential energy in biological systems?

Accepted Answer

Kinetic energy is the energy of motion, such as thermal energy, while potential energy is stored in the position or configuration of molecules, such as chemical energy.

Question 2

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

Accepted Answer

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

Question 3

Which equation correctly represents the standard free-energy change for a chemical reaction?

Accepted Answer

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

Question 4

A reaction has $$ \Delta G \u003c 0 . $$Which of the following is true about this reaction?

Accepted Answer

The reaction is exergonic and will proceed spontaneously.

Question 5

Which of the following best explains why increasing temperature generally increases the rate of a chemical reaction?

Accepted Answer

It increases the number of collisions between reactant molecules.

Question 6

In a redox reaction, what happens during the oxidation half-reaction?

Accepted Answer

Electrons are lost by a molecule.

Question 7

ATP is often called the 'energy currency' of the cell. What feature of ATP allows it to store so much potential energy?

Accepted Answer

The presence of three negatively charged phosphate groups that repel each other.

Question 8

How does ATP hydrolysis drive endergonic reactions in cells?

Accepted Answer

By transferring a phosphate group to a reactant, increasing its potential energy.

Question 9

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

Accepted Answer

Enzymes lower the activation energy required for a reaction to proceed.

Question 10

A scientist observes that increasing substrate concentration increases the rate of an enzyme-catalyzed reaction, but only up to a certain point. What is the best explanation for this observation?

Accepted Answer

All active sites of the enzyme are occupied, so the reaction rate plateaus.

Question 11

Which of the following is an example of allosteric regulation of an enzyme?

Accepted Answer

A molecule binds to a site other than the active site, changing the enzyme's shape and activity.

Question 12

Which of the following statements about feedback inhibition in metabolic pathways is correct?

Accepted Answer

The final product of the pathway inhibits an enzyme earlier in the pathway.

Question 13

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

Accepted Answer

By increasing the concentration of products.

Question 14

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 15

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

Accepted Answer

Catabolic pathways break down molecules to release energy, while anabolic pathways use energy to build molecules.

Question 16

A patient is diagnosed with a genetic disorder that prevents the production of a specific coenzyme. Which of the following is the most likely consequence?

Accepted Answer

The patient’s enzymes that require this coenzyme will have reduced or no activity.

Question 17

Which of the following scenarios best illustrates energetic coupling in a cell?

Accepted Answer

An exergonic reaction releases energy that is used to drive an endergonic reaction.

Question 18

Which of the following is true about enzyme saturation kinetics, as shown in the provided graph?

Accepted Answer

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

Question 19

Which of the following is a likely effect of a mutation that alters the primary structure of an enzyme?

Accepted Answer

The enzyme’s function may be altered due to changes in its shape.

Question 20

Which of the following best explains why enzymes are specific for particular reactions?

Accepted Answer

Each enzyme has an active site with a unique shape that only fits specific substrates.

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

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