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 mineral that helps control enzyme actions in cell mitochondria that produce and store high-energy compounds is:

• A. iron.
• B. cobalt.
• C. hemoglobin.
• D. vitamin B12.

Correct answer: A

Rationale: The correct answer is iron. Iron is essential for enzyme function and energy production within the mitochondria. While cobalt is important for certain enzymes, it is not the primary mineral involved in this specific function. Hemoglobin is a protein in red blood cells that carries oxygen, not a mineral involved in enzyme actions. Vitamin B12 is crucial for nerve function and DNA synthesis but is not directly related to controlling enzyme actions in mitochondria.

3. Which of the following is an example of a protein?

• A. Saline.
• B. Hemoglobin.
• C. Cellulose.
• D. Prostaglandins.

Correct answer: B

Rationale: Hemoglobin is a protein that carries oxygen in the blood, making it the correct answer. Choice A, Saline, is a salt solution and not a protein. Choice C, Cellulose, is a complex carbohydrate found in the cell walls of plants, not a protein. Choice D, Prostaglandins, are lipid compounds with hormone-like effects, not proteins.

4. In an analysis of the amino acid composition of foods, the amino acid occurring in the smallest amount is called:

• A. indispensable.
• B. dispensable.
• C. complementary.
• D. limiting.

Correct answer: D

Rationale: The correct answer is D, 'limiting.' In the analysis of the amino acid composition of foods, the amino acid that occurs in the smallest amount is referred to as the limiting amino acid. This term is used because when one essential amino acid is deficient, it limits the synthesis of proteins, making it crucial in determining protein quality. Choices A, B, and C are incorrect. 'Indispensable' and 'dispensable' refer to the essentiality of amino acids, and 'complementary' does not describe the concept of the amino acid occurring in the smallest amount.

5. During the process of deamination, the nitrogen portion of amino acids is converted to:

• A. ammonia.
• B. protein.
• C. purines.
• D. glycogen.

Correct answer: A

Rationale: During the process of deamination, the nitrogen portion of amino acids is converted to ammonia. This occurs in the liver as part of the process to remove excess nitrogen from the body. Choice B, 'protein,' is incorrect as deamination breaks down amino acids rather than synthesizing proteins. Choice C, 'purines,' is incorrect as purines are a type of nitrogenous base found in DNA and RNA, not a product of deamination. Choice D, 'glycogen,' is incorrect as glycogen is a storage form of glucose and not a product of amino acid deamination.

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