Nursing Elites

1. At what pH does the digestion of protein by pepsin in the stomach require?

• A. 1.8 and 3.5.
• B. 4.8 and 7.0.
• C. 6.8 and 8.5.
• D. 7.8 and 10.0.

Correct answer: A

Rationale: The correct answer is A: 1.8 and 3.5. Pepsin, an enzyme involved in protein digestion, functions optimally in an acidic environment, specifically between pH 1.8 and 3.5. This low pH is necessary for pepsin to break down proteins effectively. Choices B, C, and D are incorrect because pepsin requires a highly acidic environment, ruling out the pH ranges listed in those options.

2. The rate of gastric emptying depends on the:

• A. time of day food is consumed.
• B. composition of food consumed.
• C. rate of food consumption.
• D. frequency of eating.

Correct answer: B

Rationale: The rate at which the stomach empties its contents is primarily determined by the composition of the food consumed. Foods high in fat and protein tend to slow down gastric emptying, while foods high in carbohydrates usually pass through more quickly. Therefore, the composition of food consumed directly impacts the rate of gastric emptying. Choices A, C, and D are incorrect as they do not directly affect the rate of gastric emptying.

3. People with phenylketonuria should avoid foods made with which nonnutritive sweetener?

• A. acesulfame-K
• B. aspartame
• C. saccharin
• D. sucralose

Correct answer: B

Rationale: People with phenylketonuria should avoid aspartame because it contains phenylalanine, which they cannot metabolize. Acesulfame-K, saccharin, and sucralose do not contain phenylalanine and are safe for individuals with phenylketonuria. Therefore, the correct answer is B. Acesulfame-K, saccharin, and sucralose are incorrect choices because they do not pose a risk for individuals with phenylketonuria due to the absence of phenylalanine in their composition.

4. Ketones are produced when:

• A. carbohydrate stores are depleted.
• B. excess protein is consumed.
• C. protein stores are depleted.
• D. fat stores are depleted.

Correct answer: A

Rationale: Ketones are produced when the body uses fat for energy due to the depletion of carbohydrate stores. When carbohydrate stores are depleted, the body turns to fat as its primary source of energy, leading to the production of ketones. Excess protein consumption does not directly lead to ketone production. Similarly, the depletion of protein stores or fat stores is not directly related to the production of ketones.

5. In a low-carbohydrate diet, most of the calories are supplied by:

• A. proteins.
• B. fats.
• C. carbohydrates.
• D. vitamins.

Correct answer: B

Rationale: In a low-carbohydrate diet, fats become the primary source of calories as carbohydrate intake is restricted. Proteins can contribute to caloric intake but are not the primary source in a low-carbohydrate diet. Carbohydrates are intentionally limited in this diet, so they do not supply most of the calories. Vitamins are essential nutrients but do not provide calories.

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