Question 1

Which of the following best describes substrate-level phosphorylation?

Accepted Answer

ATP is produced by transferring a phosphate group directly from a high-energy compound to ADP.

Question 2

During oxidative phosphorylation, what is the final electron acceptor in aerobic respiration?

Accepted Answer

Oxygen ($$O_2)$$

Question 3

Which process is responsible for generating the majority of ATP in prokaryotic cells during aerobic respiration?

Accepted Answer

Electron Transport Chain (ETC)

Question 4

In the enzyme-catalyzed reaction shown in Figure 5.6, what is the role of the enzyme?

Accepted Answer

It lowers the activation energy required for the reaction.

Question 5

Which of the following is an example of competitive inhibition?

Accepted Answer

Sulfa drugs compete with PABA in folic acid synthesis.

Question 6

Which statement correctly distinguishes noncompetitive inhibition from competitive inhibition?

Accepted Answer

Noncompetitive inhibitors bind to a different site (allosteric site) and cannot be overcome by adding more substrate.

Question 7

What is the main purpose of the Pentose Phosphate Pathway (PPP) in microbial metabolism?

Accepted Answer

To produce NADPH and 5-carbon sugars for biosynthesis.

Question 8

Which of the following carrier molecules in the electron transport chain contains iron atoms bound to sulfur and transfers only electrons?

Accepted Answer

Iron-Sulfur Proteins

Question 9

Why does FADH$$_2$$ yield less ATP than NADH during oxidative phosphorylation?

Accepted Answer

FADH$$_2$$ enters the electron transport chain at a later point, bypassing the first proton pump.

Question 10

Which equation represents the conversion of PEP to pyruvate via substrate-level phosphorylation?

Accepted Answer

$$PEP + ADP \rightarrow Pyruvate + ATP$$

Question 11

Which of the following is NOT a function of enzymes in microbial metabolism?

Accepted Answer

They are permanently changed during the reaction.

Question 12

Which process occurs in the thylakoid membranes and uses light energy to generate ATP?

Accepted Answer

Photophosphorylation

Question 13

What is the total net ATP yield per glucose molecule in prokaryotes during aerobic respiration?

Accepted Answer

$$\approx 38$$ ATP

Question 14

Which of the following is a key concept of chemiosmosis?

Accepted Answer

Movement of protons down their gradient powers ATP formation.

Question 15

Which coenzyme is commonly involved in redox reactions as an electron carrier in microbial metabolism?

Accepted Answer

NAD$$^+$$

Question 16

Which of the following statements about feedback inhibition is correct?

Accepted Answer

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

Question 17

Which step in cellular respiration produces the most NADH per glucose molecule?

Accepted Answer

Krebs Cycle (Citric Acid Cycle)

Question 18

Which of the following is a function of the Pentose Phosphate Pathway (PPP) that distinguishes it from glycolysis?

Accepted Answer

Production of NADPH for biosynthetic reactions

Question 19

Which analogy best describes substrate-level phosphorylation?

Accepted Answer

Handing cash directly from one person to another

Question 20

Which of the following is true regarding the location of oxidative phosphorylation in eukaryotes?

Accepted Answer

It occurs in the inner mitochondrial membrane.

Microbial Metabolism: ATP Synthesis, Enzyme Activity, and Pathways

Study Guide - Practice Questions