Q: Which equation correctly represents the complete oxidation of glucose during cellular respiration?

$$\mathrm{C$$_{6}$$H_{12}O$$_{6}} + 6\mathrm{O_{2}} \rightarrow 6\mathrm{CO_{2}} + 6\mathrm{$$H_{2}O$$} + \text{energy}$

Question 1

Which of the following best describes the main function of cellular metabolism in living organisms?

Accepted Answer

To convert biochemical energy from food into ATP, which serves as the main fuel for cellular processes.

Question 2

Which equation correctly represents the complete oxidation of glucose during cellular respiration?

Accepted Answer

$$\mathrm{C$$_{6}$$H_{12}O$$_{6}} + 6\mathrm{O_{2}} ightarrow 6\mathrm{CO_{2}} + 6\mathrm{$$H_{2}O$$} + 	ext{energy}$

Question 3

Which of the following statements about ATP is TRUE?

Accepted Answer

ATP is unstable and must be continuously synthesized by cells.

Question 4

Which of the following is a catabolic pathway?

Accepted Answer

Glycolysis, because it breaks down glucose to harvest energy.

Question 5

Which of the following is NOT a common theme in metabolic pathways?

Accepted Answer

Enzymes in a pathway work independently and do not interact.

Question 6

A patient is given a drug that acts as a competitive inhibitor for a key metabolic enzyme. Which of the following best describes how this drug works?

Accepted Answer

It binds to the enzyme's active site, preventing the substrate from binding.

Question 7

Which of the following is an example of feedback inhibition in a metabolic pathway?

Accepted Answer

The final product of a pathway binds to an enzyme early in the pathway, reducing its activity.

Question 8

Which of the following best explains the effect of phosphorylation on enzyme activity?

Accepted Answer

Phosphorylation causes a conformational change in the enzyme, which can either activate or inactivate it.

Question 9

Which of the following is a requirement for cellular respiration in all cells?

Accepted Answer

An energy source to generate ATP and a source of carbon for synthesizing macromolecules.

Question 10

Which of the following best describes the role of allosteric regulation in enzyme activity?

Accepted Answer

A regulatory molecule binds to a site other than the active site, causing a change in enzyme activity.

Question 11

Which of the following molecules can serve as fuel sources for cellular respiration?

Accepted Answer

Carbohydrates, lipids, and proteins

Question 12

A mutation causes an enzyme in glycolysis to lose its function. Which of the following is the most likely consequence for the cell?

Accepted Answer

The cell's ability to produce ATP through cellular respiration will be reduced.

Question 13

Which of the following best explains why cells cannot store large amounts of ATP?

Accepted Answer

ATP is unstable and must be synthesized continuously as needed.

Question 14

Which of the following is an anabolic pathway?

Accepted Answer

Synthesis of proteins from amino acids

Question 15

Which of the following best describes the relationship between catabolic and anabolic pathways?

Accepted Answer

Catabolic pathways provide energy and building blocks for anabolic pathways.

Question 16

A scientist discovers a new enzyme that is only active when a specific molecule binds to a site other than the active site. What type of regulation is this?

Accepted Answer

Allosteric activation

Question 17

Which of the following is a real-life example of feedback inhibition?

Accepted Answer

The end product of the amino acid isoleucine biosynthesis pathway inhibits the first enzyme in the pathway.

Question 18

Which of the following best explains why metabolic pathways are regulated?

Accepted Answer

To maintain a constant balance (homeostasis) between catabolic and anabolic processes.

Question 19

Which of the following statements about covalent modification of enzymes is TRUE?

Accepted Answer

Covalent modification, such as phosphorylation, can cause a reversible conformational change in enzyme activity.

Question 20

Which of the following best describes the role of intermediates from cellular respiration?

Accepted Answer

They serve as building blocks for the synthesis of other molecules such as amino acids, nucleotides, and fatty acids.

Molecules & Energy: Enzymes, Metabolism, and Cellular Respiration

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