Question 1

Which of the following statements best describes the process of beta-oxidation in prokaryotes?

Accepted Answer

Beta-oxidation occurs in the cytosol and produces acetyl-CoA, FADH$$_2$$, and NADH.

Question 2

During triglyceride catabolism, what is the fate of glycerol after it is separated from fatty acids by lipases?

Accepted Answer

It is converted into DHAP, which enters glycolysis.

Question 3

Which of the following best explains why prokaryotes secrete proteases during protein catabolism?

Accepted Answer

Proteases are needed to hydrolyze proteins into amino acids that are small enough to be transported into the cell.

Question 4

After deamination of amino acids during protein catabolism, what are the possible fates of the removed amino group ($$\mathrm{NH_2$}$$)?

Accepted Answer

It can be recycled to make other amino acids, converted to ammonia ($$\mathrm{NH_3$}$$), or to ammonium ion ($$\mathrm{NH_4$^+}).$$

Question 5

Which pigment is primarily used by green plants, algae, photosynthetic protozoa, and cyanobacteria for capturing light energy?

Accepted Answer

Chlorophyll a

Question 6

In photosynthetic eukaryotes, where are protons pumped during the light-dependent reactions of photosynthesis?

Accepted Answer

From the stroma into the thylakoid space

Question 7

Which of the following statements about cyclic and noncyclic photophosphorylation is correct?

Accepted Answer

Noncyclic photophosphorylation produces ATP and reduces NADP$$^+ to $$NADPH.

Question 8

In oxygenic photosynthetic organisms, what is the source of electrons for the light-dependent reactions?

Accepted Answer

Water ($$\mathrm{H_2O})$$

Question 9

Which enzyme catalyzes the attachment of carbon dioxide to ribulose 1,5-bisphosphate (RuBP) in the Calvin-Benson cycle?

Accepted Answer

Rubisco

Question 10

During the Calvin-Benson cycle, what is the net result of reducing six molecules of 3-phosphoglyceric acid using NADPH?

Accepted Answer

Six molecules of glyceraldehyde 3-phosphate (G3P) are produced.

Question 11

Which metabolic pathways provide the 12 precursor metabolites required for the biosynthesis of all macromolecules and cellular structures in E. coli?

Accepted Answer

Glycolysis, citric acid cycle, and pentose phosphate pathway

Question 12

Which of the following statements about gluconeogenesis is correct?

Accepted Answer

Gluconeogenesis is the synthesis of sugars from noncarbohydrate precursors and is highly endergonic.

Question 13

A patient is found to have a metabolic disorder that prevents the formation of acetyl-CoA from fatty acids. Which process would be directly impaired?

Accepted Answer

Entry of fatty acid-derived carbons into the citric acid cycle

Question 14

Which of the following is the most energy-efficient form of energy storage in cells?

Accepted Answer

Triglycerides

Question 15

Which of the following is the most common form of lipid synthesized in cells?

Accepted Answer

Phospholipids

Question 16

A researcher is studying a photosynthetic bacterium that uses hydrogen sulfide ($$\mathrm{H_2S}) as an $$electron donor. Which type of photosynthesis is this organism performing?

Accepted Answer

Anoxygenic photosynthesis

Question 17

Which of the following best explains why E. coli can synthesize all 12 precursor metabolites required for cellular biosynthesis?

Accepted Answer

E. coli has all the necessary enzymes for glycolysis, the citric acid cycle, and the pentose phosphate pathway.

Question 18

Which of the following is a real-life application of the pentose phosphate pathway in bacteria?

Accepted Answer

It provides NADPH for biosynthetic reactions such as fatty acid synthesis.

Question 19

A mutation in a photosynthetic organism prevents the reduction of NADP$$^+ to $$NADPH during the light-dependent reactions. Which process would be directly affected?

Accepted Answer

The Calvin-Benson cycle (light-independent reactions)

Question 20

Which of the following best describes the role of carotenoids in cells?

Accepted Answer

They are lipids that function as accessory pigments in photosynthesis.

Microbial Metabolism: Catabolism and Anabolism of Lipids, Proteins, and Photosynthesis

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