Nursing Elites

1. Which tissue has the highest rate of protein turnover?

• A. Skin
• B. Intestinal mucosa
• C. Muscle
• D. Adipose tissue

Correct answer: B

Rationale: The correct answer is B: Intestinal mucosa. The intestinal mucosa has the highest rate of protein turnover due to its rapid cell renewal. The skin, muscle, and adipose tissue do not exhibit protein turnover rates as high as the intestinal mucosa. Skin cells turnover relatively slower compared to the rapid renewal of intestinal mucosa cells. Muscles have a moderate rate of protein turnover, while adipose tissue has a lower turnover rate compared to the other tissues mentioned.

2. Two amino acids are chemically joined by a:

• A. double bond.
• B. hydrogen bond.
• C. carboxyl bond.
• D. peptide bond.

Correct answer: D

Rationale: The correct answer is D, peptide bond. A peptide bond is formed through a dehydration synthesis reaction between the amine group of one amino acid and the carboxyl group of another amino acid. This bond is crucial in protein synthesis. Choices A, B, and C are incorrect. A double bond involves sharing two pairs of electrons, a hydrogen bond is a weak attraction between a hydrogen atom and an electronegative atom, and a carboxyl bond is not a common term in biochemistry.

3. 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.

4. Which hormone is responsible for stimulating the gallbladder to contract and release bile?

• A. gastric lipase
• B. cholecystokinin
• C. vitamin D
• D. enterokinin

Correct answer: B

Rationale: Cholecystokinin (CCK) is the correct answer. It is the hormone responsible for stimulating the gallbladder to contract and release bile to aid in fat digestion. Gastric lipase (Choice A) is an enzyme that breaks down fats in the stomach, not a hormone involved in gallbladder function. Vitamin D (Choice C) is important for calcium absorption and bone health, but it is not directly related to gallbladder function. Enterokinin (Choice D) is a peptide hormone that affects smooth muscle contractions in the gastrointestinal tract, but it is not specifically responsible for stimulating the gallbladder to release bile.

5. What substance activates pepsinogen to pepsin?

• A. Bile
• B. Gastrin
• C. Secretin
• D. Hydrochloric acid

Correct answer: D

Rationale: The correct answer is D: Hydrochloric acid. Hydrochloric acid in the stomach plays a crucial role in converting pepsinogen into its active form, pepsin, which is necessary for digesting proteins. Bile (Choice A) is involved in the emulsification of fats, not in the activation of pepsinogen. Gastrin (Choice B) is a hormone that stimulates the secretion of gastric acid but does not directly activate pepsinogen. Secretin (Choice C) is a hormone that regulates the pH of the duodenum but is not responsible for the activation of pepsinogen.

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