Nursing Elites

1. What function does cholesterol, a phospholipid, serve within the cell membrane?

• A. It builds up fats to make the structure more flexible
• B. It allows protein channels to form
• C. It makes the structure very rigid and impermeable
• D. It stabilizes the membrane structure

Correct answer: D

Rationale: Cholesterol helps to maintain the fluidity and stability of the cell membrane by fitting between the phospholipid molecules. Choice A is incorrect because cholesterol does not build up fats in the cell membrane. Choice B is incorrect as protein channels are formed by proteins, not cholesterol. Choice C is incorrect as cholesterol actually helps regulate the fluidity of the membrane, making it less rigid and more permeable.

2. In which step of cellular respiration is the most adenosine triphosphate (ATP) created?

• A. Electron transport chain
• B. Glycolysis
• C. Citric acid cycle (the Krebs cycle)
• D. All of these produce equal amounts of ATP

Correct answer: A

Rationale: The electron transport chain is the step in cellular respiration that generates the most ATP. During this step, up to 34 ATP molecules can be produced from a single glucose molecule. Choice B, Glycolysis, produces a smaller amount of ATP (2 ATP molecules per glucose), and choice C, Citric acid cycle, produces some ATP but not as much as the electron transport chain. Choice D is incorrect because different steps of cellular respiration produce varying amounts of ATP, with the electron transport chain being the most efficient in ATP generation.

3. What do prokaryotic cells lack in comparison to eukaryotic cells?

• A. A defined nucleus and a series of membrane-bound organelles
• B. A defined nucleus and no membrane-bound organelles
• C. No defined nucleus and a series of membrane-bound organelles
• D. No defined nucleus and no membrane-bound organelles

Correct answer: D

Rationale: Prokaryotic cells are characterized by the absence of a defined nucleus and membrane-bound organelles. Choice A is incorrect because prokaryotic cells lack membrane-bound organelles. Choice B is incorrect because prokaryotic cells lack both a defined nucleus and membrane-bound organelles. Choice C is incorrect as prokaryotic cells have no defined nucleus. Therefore, the correct answer is D.

4. Which organelle has the ability to hydrolyze fats, nucleic acids, proteins, and sugars?

• A. Chloroplasts
• B. Mitochondria
• C. Lysosomes
• D. Ribosomes

Correct answer: C

Rationale: The correct answer is C, Lysosomes. Lysosomes contain hydrolytic enzymes that are capable of breaking down various biomolecules such as fats, nucleic acids, proteins, and sugars. This organelle acts as the 'digestive system' of the cell. Choices A, B, and D are incorrect because chloroplasts are involved in photosynthesis, mitochondria are responsible for energy production, and ribosomes are responsible for protein synthesis, not the hydrolysis of biomolecules.

5. What cell structure is responsible for efficiently packaging DNA into a small volume to fit into the nucleus of a cell and protect the DNA structure and sequence?

• A. Golgi apparatus
• B. Chromatin
• C. Smooth endoplasmic reticulum
• D. Mitochondria

Correct answer: B

Rationale: Chromatin is the correct answer. Chromatin is responsible for packaging DNA into a more compact, dense structure to fit into the nucleus and protect the DNA. The Golgi apparatus is involved in processing and packaging proteins, not DNA. Smooth endoplasmic reticulum is involved in lipid metabolism and detoxification. Mitochondria are known as the powerhouse of the cell responsible for energy production, not DNA packaging.

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