Nursing Elites

1. 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.

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. 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.

4. Which component of fat can be used to make glucose through gluconeogenesis?

• A. Glycogen
• B. Fatty acids
• C. Glycerol
• D. Monoglyceride

Correct answer: C

Rationale: The correct answer is 'Glycerol.' Glycerol, a component of fat, can be converted into glucose through gluconeogenesis. Glycogen (Choice A) is a polysaccharide stored in animals, not a component of fat. Fatty acids (Choice B) are used primarily for energy production through beta-oxidation, not for gluconeogenesis. Monoglyceride (Choice D) is a molecule formed during fat digestion, but it is not the component of fat that can be used to make glucose.

5. Which component of protein contains nitrogen?

• A. Amino group
• B. Carboxyl group
• C. Peptide bond
• D. Side chain

Correct answer: A

Rationale: The correct answer is the amino group. Amino groups are functional groups found in amino acids, which are the building blocks of proteins. These groups contain nitrogen and are essential for the structure and function of proteins. The carboxyl group (choice B) contains carbon, oxygen, and hydrogen, while the peptide bond (choice C) is a covalent bond formed between amino acids in a protein chain. The side chain (choice D) refers to the unique chemical structure attached to the central carbon of an amino acid and varies among different amino acids, but it does not specifically contain nitrogen.

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