Nursing Elites

1. Which cellular structure is largely protective in function?

• A. Mitochondrion
• B. Vacuole
• C. Cell membrane
• D. Ribosome

Correct answer: C

Rationale: The correct answer is C: Cell membrane. The cell membrane, also known as the plasma membrane, is largely protective in function as it serves as a selectively permeable barrier that surrounds the cell, providing structural support and helping to maintain cell integrity. It regulates the movement of substances in and out of the cell, thus protecting the cell from harmful external factors while allowing essential nutrients to enter. Mitochondrion (choice A) is responsible for energy production, not primarily protective. Vacuole (choice B) is mainly involved in storage and transport. Ribosome (choice D) is involved in protein synthesis, not protective functions.

2. Most enzymes are made up of what?

• A. proteins
• B. lipids
• C. starches
• D. simple sugars

Correct answer: A

Rationale: Most enzymes are made up of proteins. Proteins are large biomolecules composed of amino acids that are vital for the structure and function of enzymes. Enzymes act as catalysts in biochemical reactions, speeding up the rate of chemical reactions in living organisms. They exhibit high specificity and efficiency due to their unique protein structures. Lipids, starches, and simple sugars are not typically the primary components of enzymes, making them incorrect choices.

3. Which of the following is true of Glycolysis?

• A. It requires the absence of Oxygen
• B. It occurs in the presence of Oxygen
• C. It is the final step of fermentation
• D. It is the final step of anaerobic respiration

Correct answer: B

Rationale: Glycolysis is the first step in cellular respiration and can occur in both aerobic (presence of oxygen) and anaerobic (absence of oxygen) conditions. In aerobic respiration, glycolysis takes place in the presence of oxygen and continues with the Krebs cycle and the electron transport chain. So, glycolysis does not require the absence of oxygen but can occur in its presence as part of the overall process of aerobic respiration. Choice A is incorrect because glycolysis can occur in the presence of oxygen. Choice C is incorrect because glycolysis is not the final step of fermentation; it is the initial step. Choice D is incorrect because glycolysis is not the final step of anaerobic respiration; it is the first step, followed by further processes to complete anaerobic respiration.

4. Which of the following types of hormones can diffuse through the cell membrane to bind to receptors inside the cell and stimulate a chemical response to a target cell?

• A. fat-soluble hormones
• B. amino acid derivatives
• C. hydrophilic hormones
• D. water-soluble hormones

Correct answer: A

Rationale: The correct answer is A: fat-soluble hormones. Fat-soluble hormones are able to diffuse through the cell membrane to bind to receptors inside the cell. This is because they are lipophilic, allowing them to cross the lipid bilayer easily. Once inside the cell, fat-soluble hormones can directly affect gene expression or cell function. Choice B, amino acid derivatives, and choice C, hydrophilic hormones, are not able to diffuse through the cell membrane as they are not lipophilic. Therefore, they cannot bind to receptors inside the cell. Choice D, water-soluble hormones, also cannot diffuse through the cell membrane as it is hydrophilic, making it unable to reach receptors inside the cell.

5. If a hard-boiled egg is placed in a beaker of saltwater, what will happen to the egg?

• A. Expand because water will move into the egg
• B. Shrivel because water will leave the egg
• C. Remain the same
• D. None of the above

Correct answer: B

Rationale: The correct answer is B. When a hard-boiled egg is placed in a beaker of saltwater, the egg will shrivel because water will leave the egg through osmosis. Osmosis is the movement of water from an area of lower solute concentration to an area of higher solute concentration, in this case, from the egg into the saltwater. The higher concentration of solute in the saltwater causes water to move out of the egg, leading to the egg shrinking or shriveling. Choices A, C, and D are incorrect because the egg will not expand, remain the same, or have an outcome different from shriveling when placed in a beaker of saltwater.

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