Nursing Elites

1. Which level of protein structure is defined by the folds and coils of the protein's polypeptide backbone?

• A. Primary
• B. Secondary
• C. Tertiary
• D. Quaternary

Correct answer: B

Rationale: The correct answer is B: Secondary. The secondary structure of a protein is defined by the folds and coils of the protein's polypeptide backbone. This level of structure is characterized by the formation of alpha helices and beta sheets, which are stabilized by hydrogen bonds between amino acids along the polypeptide chain. Choice A, Primary, refers to the linear sequence of amino acids in the protein. Choice C, Tertiary, involves the 3D folding of the entire polypeptide chain. Choice D, Quaternary, pertains to the arrangement of multiple polypeptide subunits in a protein complex.

2. What are isotopes?

• A. Atoms of the same element with different numbers of protons.
• B. Atoms of the same element with different numbers of neutrons.
• C. Atoms of different elements with the same number of protons.
• D. Atoms of different elements with the same number of electrons.

Correct answer: B

Rationale: Isotopes are atoms of the same element with different numbers of neutrons. While isotopes share the same number of protons, which determines the element, they differ in the number of neutrons. This variance in neutron count results in isotopes having different atomic masses. Choice A is incorrect because isotopes have the same number of protons (same element) but differ in the number of neutrons. Choice C is incorrect as it describes atoms of different elements, not isotopes of the same element. Choice D is also incorrect because isotopes can have different numbers of electrons, but what defines isotopes is the variation in neutron numbers.

3. What are the small, finger-like projections in the small intestines called?

• A. Cilia
• B. Rugae
• C. Trachea
• D. Villi

Correct answer: D

Rationale: The correct answer is D: Villi. Villi are small, finger-like projections in the small intestine that increase the surface area for absorption, aiding in the absorption of nutrients. Cilia (Choice A) are tiny hair-like structures found in various parts of the body but are not present in the small intestine. Rugae (Choice B) are folds in the mucosa of the stomach that allow for its expansion during digestion. The trachea (Choice C) is part of the respiratory system, responsible for carrying air to and from the lungs, and is not related to the small intestine.

4. Which type of chemical reaction produces a salt?

• A. An oxidation reaction
• B. A neutralization reaction
• C. A synthesis reaction
• D. A decomposition reaction

Correct answer: B

Rationale: The correct answer is B, a neutralization reaction. In a neutralization reaction, an acid and a base react to produce a salt and water. This process involves the combination of H+ ions from the acid and OH- ions from the base to form water, while the remaining ions combine to form a salt. Therefore, a neutralization reaction is the specific type of chemical reaction that produces a salt. Choices A, C, and D are incorrect. An oxidation reaction involves the loss of electrons, a synthesis reaction involves the formation of a compound from simpler substances, and a decomposition reaction involves the breakdown of a compound into simpler substances. None of these reactions directly lead to the production of a salt, making them incorrect choices in this context.

5. A person wakes up with a fever. The body begins its response to locate the origin of the problem and fix it. What type of feedback mechanism is this?

• A. Equal
• B. Negative
• C. Neutral
• D. Positive

Correct answer: B

Rationale: This scenario describes a negative feedback mechanism. When the body detects a fever, it initiates responses to lower the temperature back to normal levels. Negative feedback mechanisms work to counteract changes and maintain homeostasis in the body. Choice A ('Equal') is incorrect as feedback mechanisms aim to restore balance, not maintain an equal state. Choice C ('Neutral') is incorrect as it does not describe the corrective nature of negative feedback. Choice D ('Positive') is incorrect as it would amplify the fever rather than regulate it.

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