Nursing Elites

1. Which monosaccharide only occurs naturally in foods in combination with another sugar as a disaccharide?

• A. Fructose.
• B. Galactose.
• C. Sucrose.
• D. Maltose.

Correct answer: B

Rationale: The correct answer is B, galactose. Galactose naturally occurs in foods only when it is combined with glucose to form lactose, a disaccharide found in milk. Fructose is a monosaccharide found in fruits and honey. Sucrose is a disaccharide composed of glucose and fructose, commonly known as table sugar. Maltose is a disaccharide formed by the combination of two glucose molecules.

2. The sugar to which all other sugars are converted during human metabolism is:

• A. sucrose
• B. fructose
• C. glucose
• D. maltose

Correct answer: C

Rationale: Glucose is the primary sugar used by the body for energy and is converted from other sugars during metabolism. Sucrose is a disaccharide composed of glucose and fructose, not the end product of sugar metabolism. Fructose is a simple sugar found in fruits but needs to be converted to glucose for cellular energy. Maltose is a disaccharide composed of two glucose units and is not the final product of sugar metabolism in humans.

3. What is the mechanism that is essential for the absorption of monosaccharides?

• A. Phosphorylation
• B. Active transport
• C. Passive diffusion
• D. Facilitated diffusion

Correct answer: B

Rationale: Active transport is the mechanism essential for the absorption of monosaccharides in the intestine. This process requires energy to move molecules against their concentration gradient, allowing for the absorption of monosaccharides efficiently. Phosphorylation, the process of adding a phosphate group to a molecule, is not directly involved in the absorption of monosaccharides. Passive diffusion, a process that does not require energy, is not the primary mechanism for absorbing monosaccharides due to their large size. Facilitated diffusion, a type of passive transport that involves carrier proteins, is not the primary mechanism for monosaccharide absorption, as monosaccharides require active transport for efficient absorption.

4. 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.

5. How is resistant starch digested in the colon?

• A. bacterial fermentation.
• B. pancreatic amylase.
• C. hydrochloric acid.
• D. villi and microvilli.

Correct answer: A

Rationale: In the colon, resistant starch is digested by bacterial fermentation. The correct answer is A. During this process, short-chain fatty acids are produced. Pancreatic amylase, as mentioned in choice B, is responsible for breaking down starch in the small intestine, not in the colon. Choice C, hydrochloric acid, functions in the stomach to aid in the digestion of proteins, not starch. Villi and microvilli, as stated in choice D, are structures in the small intestine that absorb nutrients; they do not participate in the digestion of resistant starch in the colon.

Similar Questions