Nursing Elites

1. Pepsinogen secreted by the gastric cells is converted into pepsin by:

• A. enterokinase
• B. hydrochloric acid
• C. gastric lipase
• D. pancreatic lipase

Correct answer: B

Rationale: Pepsinogen is converted into its active form, pepsin, by hydrochloric acid in the stomach. Hydrochloric acid helps in unfolding the pepsinogen molecule to transform it into pepsin, which is crucial for protein digestion. Therefore, the correct answer is hydrochloric acid (choice B). Enterokinase (choice A) is an enzyme produced in the small intestine that activates trypsinogen into trypsin, not pepsinogen. Gastric lipase (choice C) is an enzyme that digests fats, not involved in converting pepsinogen to pepsin. Pancreatic lipase (choice D) is an enzyme produced by the pancreas that aids in breaking down fats in the small intestine, not part of the process of pepsin activation.

2. Which hormone stimulates the gallbladder to contract?

• A. Secretin.
• B. Cholecystokinin (CCK).
• C. Gastrin.
• D. Gastric inhibitory polypeptide (GIP).

Correct answer: B

Rationale: Cholecystokinin (CCK) is the hormone responsible for stimulating the gallbladder to contract and release bile into the small intestine. Secretin primarily acts on the pancreas to stimulate the secretion of bicarbonate-rich fluid. Gastrin functions in the stimulation of gastric acid secretion, while Gastric inhibitory polypeptide (GIP) plays a role in inhibiting gastric acid secretion and stimulating insulin release.

3. Which pathogenic bacterium is associated with peptic ulcer disease and gastric cancer?

• A. Lactobacillus.
• B. Bifidobacterium.
• C. H. pylori.
• D. E. coli.

Correct answer: C

Rationale: The correct answer is H. pylori. This bacterium is known to be associated with the development of peptic ulcers and an increased risk of gastric cancer. Lactobacillus (Choice A) and Bifidobacterium (Choice B) are probiotic bacteria that are beneficial to human health and not associated with causing these conditions. E. coli (Choice D) is a diverse group of bacteria, some of which can be pathogenic, but they are not primarily linked to peptic ulcers and gastric cancer like H. pylori.

4. A chemical feature that distinguishes a saturated fatty acid from an unsaturated fatty acid is the:

• A. arrangement of carbon atoms.
• B. number of oxygen molecules.
• C. number of double bonds.
• D. food source.

Correct answer: C

Rationale: The correct answer is C. Saturated fatty acids have no double bonds between carbon atoms, while unsaturated fatty acids have one or more double bonds. Therefore, the number of double bonds is the chemical feature that distinguishes a saturated fatty acid from an unsaturated fatty acid. Choices A, B, and D are incorrect because the distinguishing factor between saturated and unsaturated fatty acids lies in the presence or absence of double bonds, not in the arrangement of carbon atoms, number of oxygen molecules, or food source.

5. How can cholesterol absorption be decreased?

• A. Vitamin K.
• B. Plant sterols.
• C. Trans fats.
• D. Phospholipids.

Correct answer: B

Rationale: The correct answer is B: Plant sterols. Plant sterols can reduce cholesterol absorption by competing with cholesterol for absorption sites. Vitamin K, choice A, does not have a significant impact on cholesterol absorption. Trans fats, choice C, are known to increase cholesterol levels rather than decrease absorption. Phospholipids, choice D, play a role in cell structure and are not directly involved in reducing cholesterol absorption.

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