Q: Which of the following equations correctly represents the process of cellular respiration?

$$\mathrm{C_6H_{12}O_6$} + 6\mathrm{O_2$} \rightarrow 6\mathrm{CO_2$} + 6\mathrm{H_2O} + \text{ATP}$$

Question 1

Which of the following best describes a metabolic pathway?

Accepted Answer

A series of enzyme-catalyzed reactions that transform a starting molecule into a final product.

Question 2

Which law of thermodynamics states that energy cannot be created or destroyed, only transformed?

Accepted Answer

The First Law of Thermodynamics

Question 3

A skier at the top of a hill has which type of energy, and what happens to this energy as they ski down?

Accepted Answer

Potential energy; it is converted to kinetic energy.

Question 4

Which of the following equations correctly represents the process of cellular respiration?

Accepted Answer

$$\mathrm{C_6H_{12}O_6$} + 6\mathrm{O_2$} ightarrow 6\mathrm{CO_2$} + 6\mathrm{H_2O} + 	ext{ATP}$$

Question 5

Which of the following statements about enzymes is TRUE?

Accepted Answer

Enzymes lower the activation energy barrier, speeding up reactions.

Question 6

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

Accepted Answer

The synthesis of protein from amino acids.

Question 7

What is the main role of ATP in cellular metabolism?

Accepted Answer

To couple exergonic and endergonic reactions by providing energy.

Question 8

Which of the following best describes the effect of a competitive inhibitor on an enzyme?

Accepted Answer

It binds to the active site, preventing substrate binding.

Question 9

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

Accepted Answer

It is exergonic and releases energy.

Question 10

Which of the following is a way that enzymes lower the activation energy of a reaction?

Accepted Answer

By orienting substrates correctly and straining substrate bonds.

Question 11

Which of the following best explains feedback inhibition in a metabolic pathway?

Accepted Answer

The end product of the pathway inhibits an enzyme involved early in the pathway.

Question 12

Which of the following is an example of allosteric regulation?

Accepted Answer

A regulatory molecule binding to a site other than the active site, changing enzyme activity.

Question 13

Which of the following environmental factors can affect enzyme activity?

Accepted Answer

Both temperature and pH.

Question 14

Which of the following statements about the ATP cycle is correct?

Accepted Answer

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

Question 15

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

Accepted Answer

Cofactors are non-protein helpers required for proper enzyme function.

Question 16

A patient is prescribed a drug that acts as a noncompetitive inhibitor for a key metabolic enzyme. What is the most likely effect of increasing the substrate concentration?

Accepted Answer

The inhibition will remain because the inhibitor does not compete with the substrate for the active site.

Question 17

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

Accepted Answer

The use of ATP hydrolysis to power the active transport of sodium and potassium ions across the plasma membrane.

Question 18

Which of the following best describes the induced fit model of enzyme function?

Accepted Answer

The enzyme changes shape slightly to better fit the substrate upon binding.

Question 19

Which of the following is TRUE about the second law of thermodynamics as it applies to biological systems?

Accepted Answer

Energy transformations increase the disorder (entropy) of the universe.

Question 20

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

Accepted Answer

Exergonic reactions have $$\Delta G  0.$$

Chapter 8: Metabolism – Transforming Matter & Energy

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