Nursing Elites

1. What type of molecule forms the cell membrane and controls what enters and exits the cell?

• A. Proteins
• B. Carbohydrates
• C. Lipids
• D. Nucleic acids

Correct answer: C

Rationale: The cell membrane is primarily composed of lipids, specifically phospholipids, which form a lipid bilayer. This lipid bilayer controls what enters and exits the cell, providing a barrier that is selectively permeable. While proteins are also important components of the cell membrane and play various roles, lipids are the main structural component responsible for the membrane's permeability and function. Carbohydrates and nucleic acids are not the primary components of the cell membrane and do not have the same structural role as lipids.

2. Which of the following is a strong acid?

• A. Acetic acid (CH₃COOH)
• B. Hydrochloric acid (HCl)
• C. Citric acid
• D. Carbonic acid (H₂CO₃)

Correct answer: B

Rationale: Hydrochloric acid (HCl) is a strong acid because it completely ionizes in water to produce hydrogen ions, leading to a high concentration of H⁺ ions in solution. This characteristic makes it a strong acid. Acetic acid (CH₃COOH), citric acid, and carbonic acid (H₂CO₃) are weak acids as they only partially ionize in water, resulting in a lower concentration of H⁺ ions compared to strong acids. Therefore, hydrochloric acid is the correct choice as a strong acid.

3. When light reflects from a surface, what determines the angle of reflection?

• A. The material of the surface
• B. The wavelength of the light
• C. The angle of incidence
• D. The intensity of the light

Correct answer: C

Rationale: The angle of reflection is determined by the angle of incidence according to the law of reflection, which states that the angle of incidence is equal to the angle of reflection. When light reflects off a surface, the angle at which it strikes the surface (angle of incidence) is the key factor in determining the angle at which it reflects (angle of reflection). The material of the surface, the wavelength of the light, and the intensity of the light do not directly influence the angle of reflection in this context. Therefore, the correct answer is the angle of incidence (Choice C). The material of the surface (Choice A) does affect other properties like reflectivity but does not directly determine the angle of reflection. The wavelength of the light (Choice B) determines its color or frequency but not the angle of reflection. The intensity of the light (Choice D) is related to the brightness of the light but does not dictate the angle at which light reflects from a surface.

4. Which of the following nutrients is correctly matched with its foundational components?

• A. Carbohydrates are formed when glucose molecules bond together.
• B. Lipids consist of fatty acids and glycerol.
• C. Nucleic acids consist of nitrogenous bases, sugar, and phosphate groups.
• D. Proteins consist of strings of amino acids.

Correct answer: D

Rationale: Proteins consist of strings of amino acids. Amino acids are the basic building blocks of proteins, and they are linked together in a specific sequence to form a protein structure. This is a correct match between the nutrient (proteins) and its foundational components (amino acids). Choices A, B, and C are incorrect as they do not accurately match the foundational components of the respective nutrients. Carbohydrates are not formed by glucose molecules bonding together; they are made up of sugar molecules. Lipids consist of fatty acids and glycerol, but they are not nutrients typically associated with bonding for formation. Nucleic acids do consist of nitrogenous bases, sugar, and phosphate groups, but they are not the correct match for the question.

5. Which organelle is responsible for breaking down macromolecules, such as proteins, carbohydrates, and lipids, into their smaller building blocks?

• A. Golgi apparatus
• B. Mitochondria
• C. Lysosomes
• D. Endoplasmic reticulum

Correct answer: C

Rationale: Lysosomes are membrane-bound organelles containing digestive enzymes that break down macromolecules, such as proteins, carbohydrates, and lipids, into their smaller building blocks. These enzymes help in the process of intracellular digestion and recycling of cellular components. The Golgi apparatus is involved in processing and packaging proteins for secretion or for use within the cell. Mitochondria are responsible for producing energy in the form of ATP through cellular respiration. The endoplasmic reticulum is involved in protein synthesis and lipid metabolism. Therefore, the correct answer is 'C: Lysosomes' as they specifically function in the breakdown of macromolecules into smaller components, distinguishing them from the other organelles mentioned.

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