Nursing Elites

1. 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.

2. What is the primary function of protein in the body?

• A. Provide energy.
• B. Regulate metabolic processes.
• C. Control muscle contractions.
• D. Build tissue.

Correct answer: D

Rationale: The primary function of protein in the body is to build and repair tissues. Proteins are crucial for growth, maintenance, and repair of body tissues, including muscles, organs, and skin. While proteins can be a source of energy, their primary role is not to supply energy. Regulating metabolic processes and controlling muscle contractions are functions typically attributed to other nutrients and compounds in the body, such as vitamins and minerals.

3. 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.

4. 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.

5. The hormone secretin stimulates production of a buffering solution for the duodenum by the:

• A. stomach.
• B. liver.
• C. pancreas.
• D. oxyntic cells.

Correct answer: C

Rationale: The correct answer is C: pancreas. Secretin stimulates the pancreas to release bicarbonate, which acts as a buffering solution to neutralize the acid entering the duodenum from the stomach. This process helps in maintaining the pH balance in the small intestine. Choice A, stomach, is incorrect as the stomach does not produce the buffering solution needed for the duodenum. Choice B, liver, is incorrect because secretin does not directly stimulate the liver to produce a buffering solution. Choice D, oxyntic cells, is also incorrect as these cells in the stomach are responsible for producing gastric acid, not the buffering solution needed in the duodenum.

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