Nursing Elites

1. The pancreas secretes digestive enzymes into the small intestine. What enzyme breaks down proteins into amino acids?

• A. Pepsin
• B. Lipase
• C. Amylase
• D. Trypsin

Correct answer: D

Rationale: Trypsin is the correct enzyme that breaks down proteins into amino acids. It is produced by the pancreas and released into the small intestine to facilitate protein digestion. Pepsin is an enzyme from the stomach that also breaks down proteins, amylase targets carbohydrates, and lipase works on fats. In this context, since the question specifies the pancreas and small intestine, the correct answer is Trypsin as it is the pancreatic enzyme responsible for protein breakdown in the small intestine.

2. What is the balanced chemical equation for the reaction between sulfuric acid (H2SO4) and potassium hydroxide (KOH)?

• A. H2SO4 + KOH → K2SO4 + H2O
• B. 2H2SO4 + 2KOH → 2K2SO4 + 2H2O
• C. H2SO4 + 2KOH → K2SO4 + 2H2O
• D. H2SO4 + 2KOH → K2SO4 + H2O

Correct answer: C

Rationale: When sulfuric acid (H2SO4) reacts with potassium hydroxide (KOH), it forms potassium sulfate (K2SO4) and water (H2O). To balance the equation, 2 KOH molecules are required to react with 1 H2SO4 molecule, resulting in 1 K2SO4 molecule and 2 H2O molecules. Therefore, the balanced chemical equation is H2SO4 + 2KOH → K2SO4 + 2H2O, which corresponds to option C. Choice A is incorrect because it does not account for the correct stoichiometry between the reactants and products. Choice B incorrectly doubles all the molecules in the reaction, leading to an unbalanced equation. Choice D incorrectly balances the equation with 1 KOH molecule instead of the required 2 KOH molecules, making it unbalanced. Thus, option C is the correct balanced chemical equation for the reaction between sulfuric acid and potassium hydroxide.

3. How do hydrogen bonds in water affect its characteristics?

• A. Hydrogen bonds are not polar enough to attract non-polar molecules.
• B. Hydrogen bonds cause water to be less dense when it is a solid than when it is a liquid.
• C. Hydrogen bonds cause water to have high surface tension, allowing some organisms to move across it.
• D. Hydrogen bonds cause water to be a good solvent.

Correct answer: C

Rationale: Hydrogen bonds in water contribute to its high surface tension, enabling some organisms to move across the water's surface. This property is essential for certain insects and small animals that rely on surface tension to move or stay afloat on water. Choice A is incorrect because hydrogen bonds are polar and can attract polar and other charged molecules. Choice B is incorrect as hydrogen bonds make ice less dense than liquid water, which is a unique property. Choice D is incorrect as the ability of water to act as a good solvent is primarily due to its polarity, not just hydrogen bonding.

4. Which of the following units is used to express concentration as a mass of solute per unit volume of solution?

• A. Molality (m)
• B. Molarity (M)
• C. Weight percent (%)
• D. Parts per million (ppm)

Correct answer: A

Rationale: Molality (m) is the unit used to express concentration as a mass of solute per unit volume of solution. It is calculated by dividing the mass of solute in grams by the mass of the solvent in kilograms. Molality is preferred over molarity when there are large temperature variations as it is temperature-independent, making it a more accurate measure of concentration. Molarity (B) is the unit used to express concentration as moles of solute per liter of solution, weight percent (C) is the mass of solute per 100 parts of the total mass of the solution, and parts per million (D) is used to express very small concentrations where 1 ppm is equivalent to 1 mg of solute per liter of solution.

5. What is the process by which a cell divides into two or more new cells?

• A. Mitosis
• B. Meiosis
• C. Both mitosis and meiosis
• D. None of the above

Correct answer: A

Rationale: Mitosis is the process by which a cell divides into two identical daughter cells. This type of cell division is essential for growth, repair, and maintenance of multicellular organisms. Meiosis, on the other hand, is a type of cell division that produces gametes (sperm and egg cells) with half the number of chromosomes as the parent cell. Meiosis does not directly result in the formation of new cells, as it is specifically geared towards the production of reproductive cells. Therefore, the correct answer is A. Option C, stating both mitosis and meiosis, is incorrect because meiosis is not involved in the general process of cell division to produce new cells; it is specialized for gamete formation. Option D is incorrect because mitosis is indeed the process responsible for cell division in which one cell divides into two daughter cells, making it the accurate choice for this question.

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