Question 1

Which of the following best describes the first law of thermodynamics as it applies to biological systems?

Accepted Answer

Energy can be transferred or transformed, but cannot be created or destroyed.

Question 2

A diver climbs up a ladder to a diving platform, then jumps into the water. Which statement best explains the energy transformations involved?

Accepted Answer

The diver converts chemical energy to potential energy while climbing, and potential energy to kinetic energy while diving.

Question 3

Which equation correctly represents the change in Gibbs free energy for a reaction?

Accepted Answer

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

Question 4

Which of the following statements about exergonic reactions is correct?

Accepted Answer

Exergonic reactions release free energy and have a negative $$\Delta G.$$

Question 5

In the context of metabolism, what is the primary role of ATP?

Accepted Answer

ATP provides energy to drive endergonic reactions by coupling with exergonic reactions.

Question 6

Which of the following best describes the function of enzymes in biological systems?

Accepted Answer

Enzymes lower the activation energy barrier, speeding up reactions without being consumed.

Question 7

A metabolic pathway converts molecule A to D through intermediates B and C, each step catalyzed by a different enzyme. If enzyme 2 is inhibited, what will happen?

Accepted Answer

Molecule B will accumulate, and the pathway will stop at B.

Question 8

Which of the following is an example of a catabolic pathway?

Accepted Answer

The breakdown of glucose during cellular respiration.

Question 9

What is the effect of a competitive inhibitor on an enzyme-catalyzed reaction?

Accepted Answer

It binds to the active site, blocking substrate binding, and can be overcome by increasing substrate concentration.

Question 10

Which of the following statements about feedback inhibition is correct?

Accepted Answer

Feedback inhibition occurs when the end product of a pathway inhibits an enzyme early in the pathway.

Question 11

Which of the following best describes the second law of thermodynamics in biological systems?

Accepted Answer

Every energy transfer or transformation increases the entropy of the universe.

Question 12

Which of the following is true about the regeneration of ATP in cells?

Accepted Answer

ATP is regenerated by the addition of a phosphate group to ADP, using energy from catabolic reactions.

Question 13

A reaction has $$\Delta G = +40 kJ/$$mol. Which of the following is true?

Accepted Answer

The reaction is endergonic and requires an input of energy.

Question 14

Which of the following is an example of allosteric regulation?

Accepted Answer

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

Question 15

Which of the following best explains why living cells are considered open systems?

Accepted Answer

They absorb energy and matter from their surroundings and release waste products.

Question 16

Which of the following is a correct statement about the relationship between entropy and biological order?

Accepted Answer

Cells create order locally, but the total entropy of the system and surroundings increases.

Question 17

Which of the following is an example of an anabolic pathway?

Accepted Answer

The synthesis of proteins from amino acids.

Question 18

Which of the following best describes the role of cofactors in enzyme activity?

Accepted Answer

Cofactors are nonprotein helpers that are required for enzyme activity.

Question 19

A patient is given a drug that acts as a noncompetitive inhibitor of a key metabolic enzyme. What is the most likely effect on the enzyme's activity?

Accepted Answer

The enzyme's shape will change, reducing its activity regardless of substrate concentration.

Question 20

Which of the following is a real-life example of energy coupling in cells?

Accepted Answer

The hydrolysis of ATP is used to power the active transport of sodium and potassium ions across the cell membrane.

Chapter 8: An Introduction to Metabolism – Study Notes

Guida di studio - Domande di pratica

Study guide - Flashcard