Question 1

Which of the following best describes the relationship between catabolism and anabolism in cellular metabolism?

Accepted Answer

Catabolism generates energy and reducing power, which are then used by anabolism to build macromolecules.

Question 2

In the acetogenesis pathway of Acetobacterium woodii, what is the net ATP yield per mole of acetate produced from H$$_2$$ and CO$$_2$$?

Accepted Answer

$$0.3$$ ATP

Question 3

Which of the following is a key product of the Calvin-Benson cycle that is used for biosynthesis?

Accepted Answer

Fructose-6-phosphate

Question 4

During biological nitrogen fixation by nitrogenase, what is the minimum number of ATP molecules hydrolyzed per N$$_2$$ reduced to 2 NH$$_3$$?

Accepted Answer

$$16$$ ATP

Question 5

Which pathway is primarily responsible for the production of ribose-5-phosphate for nucleotide biosynthesis?

Accepted Answer

Pentose phosphate pathway

Question 6

What is the role of ADP-glucose (ADPG) in polysaccharide biosynthesis?

Accepted Answer

It donates glucose units for the elongation of glycogen chains.

Question 7

Which of the following statements about uridine diphosphoglucose (UDPG) is correct?

Accepted Answer

UDPG is an activated form of glucose used in the biosynthesis of polysaccharides.

Question 8

Which amino acid family is derived from intermediates of the citric acid cycle?

Accepted Answer

Glutamate family

Question 9

Which enzyme catalyzes the incorporation of ammonia into α-ketoglutarate to form glutamate?

Accepted Answer

Glutamate dehydrogenase

Question 10

Which of the following is a precursor for purine nucleotide biosynthesis?

Accepted Answer

Inosinic acid

Question 11

Which of the following best explains the source of the carbon skeletons for amino acid biosynthesis?

Accepted Answer

They are derived from intermediates of glycolysis and the citric acid cycle.

Question 12

What is the main function of acyl carrier protein (ACP) in fatty acid biosynthesis?

Accepted Answer

It holds the growing fatty acid chain during synthesis.

Question 13

Which of the following is a direct product of the pentose phosphate pathway that is essential for nucleic acid synthesis?

Accepted Answer

Ribose-5-phosphate

Question 14

Which of the following statements about the biosynthesis of fatty acids is correct?

Accepted Answer

Fatty acids are synthesized by the sequential addition of two-carbon units from acetyl-CoA.

Question 15

Which of the following best describes the role of NADPH in biosynthetic pathways?

Accepted Answer

NADPH provides reducing power for anabolic reactions.

Question 16

A bacterium is synthesizing peptidoglycan for its cell wall. Which activated sugar is most likely involved in this process?

Accepted Answer

Uridine diphosphoglucose (UDPG)

Question 17

Which of the following is a key difference between the biosynthesis of purines and pyrimidines?

Accepted Answer

Purines are synthesized from inosinic acid, while pyrimidines are synthesized from uridylate.

Question 18

A mutation in the gene encoding glutamine synthetase would most directly affect which process?

Accepted Answer

Incorporation of ammonia into glutamine

Question 19

Which of the following best explains why the Calvin-Benson cycle is important for autotrophic organisms?

Accepted Answer

It fixes CO$$_2$$ into organic molecules that can be used for biosynthesis.

Question 20

Which of the following is a real-world application of understanding the nitrogenase enzyme system?

Accepted Answer

Developing biofertilizers to enhance crop growth by increasing biological nitrogen fixation.

Microbial Biosynthesis and Metabolic Pathways

Study Guide - Practice Questions