Question 1

Which of the following best describes the role of RNA polymerase during transcription in protein synthesis?

Accepted Answer

It binds to the promoter sequence of DNA and catalyzes the formation of mRNA from a DNA template.

Question 2

During glycolysis, what is the net gain of ATP molecules per molecule of glucose?

Accepted Answer

$$2$$

Question 3

Which of the following statements about oxidative phosphorylation is correct?

Accepted Answer

It uses the energy released by the electron transport chain to pump hydrogen ions across the inner mitochondrial membrane, creating a gradient used to synthesize ATP.

Question 4

A patient is experiencing ketoacidosis. Which metabolic process is most likely occurring at an abnormally high rate?

Accepted Answer

Fatty acid breakdown (beta-oxidation) leading to excessive ketone body production.

Question 5

Which of the following best explains why enzymes are highly specific for their substrates?

Accepted Answer

The active site of an enzyme has a complementary shape to its specific substrate, allowing only certain molecules to bind.

Question 6

If a cell is unable to remove introns from pre-mRNA, what is the most likely consequence?

Accepted Answer

The resulting mRNA will contain non-coding sequences, potentially leading to a nonfunctional protein.

Question 7

Which of the following equations correctly represents the overall reaction for aerobic cellular respiration?

Accepted Answer

$$\mathrm{C_6H_{12}O_6$} + 6\ \mathrm{O_2$} \rightarrow 6\ \mathrm{CO_2$} + 6\ \mathrm{H_2O} + 32\ \mathrm{ATP}$$

Question 8

Which of the following is a correct description of the role of NADH and FADH$$_2 in $$cellular respiration?

Accepted Answer

They donate electrons to the electron transport chain, providing energy for ATP synthesis.

Question 9

A mutation causes a cell to produce a nonfunctional ATP synthase. Which process would be most directly affected?

Accepted Answer

The production of ATP during oxidative phosphorylation.

Question 10

Which of the following best describes the difference between hydrolysis and condensation reactions?

Accepted Answer

Hydrolysis uses water to break bonds, while condensation joins molecules and releases water.

Question 11

Which of the following is a correct statement about the cell cycle?

Accepted Answer

DNA replication occurs during the S phase, ensuring each daughter cell receives a complete set of chromosomes.

Question 12

A scientist adds a competitive inhibitor to an enzyme-catalyzed reaction. What is the most likely effect on the reaction rate?

Accepted Answer

The reaction rate will decrease because the inhibitor competes with the substrate for the active site.

Question 13

Which of the following best explains why the nervous system relies heavily on gluconeogenesis during prolonged fasting?

Accepted Answer

Nervous tissue requires a constant supply of glucose, and gluconeogenesis provides glucose when dietary sources are unavailable.

Question 14

Which of the following is a correct sequence of events during translation?

Accepted Answer

A charged tRNA enters the A site, peptide bond forms, ribosome shifts, and the empty tRNA exits from the E site.

Question 15

Which of the following best describes the function of coenzymes such as NAD and FAD?

Accepted Answer

They participate in enzyme-catalyzed reactions by accepting and donating electrons.

Question 16

A cell is exposed to a toxin that prevents the formation of the mitotic spindle. Which stage of mitosis would be directly affected?

Accepted Answer

Metaphase, because chromosomes cannot align at the metaphase plate without the spindle.

Question 17

Which of the following best explains why fats yield more energy per gram than carbohydrates?

Accepted Answer

Fats have more reduced carbon atoms, allowing for more electrons to be transferred to NADH and FADH$$_2$$ during oxidation.

Question 18

Which of the following is a correct statement about the law of conservation of energy as it applies to cellular metabolism?

Accepted Answer

Energy is neither created nor destroyed, but is transformed from one form to another during metabolic reactions.

Human Physiology: Protein Synthesis and Cellular Metabolism Study Notes

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