Nursing Elites

1. Which molecule allows for the selective passage of materials into and out of the cell?

• A. DNA
• B. Protein
• C. Carbohydrate
• D. Phospholipid bilayer

Correct answer: D

Rationale: The correct answer is D, the phospholipid bilayer. The phospholipid bilayer is the main component of the cell membrane, which acts as a selective barrier allowing certain molecules to pass through while blocking others. Its structure consists of hydrophilic heads facing outward towards the aqueous environments inside and outside the cell, while the hydrophobic tails face inward creating a semi-permeable barrier. DNA (A) is the genetic material of the cell and is located within the nucleus, not involved in material passage. Proteins (B) and carbohydrates (C) are important components of the cell membrane and play various roles, but they do not directly control the selective passage of materials in and out of the cell.

2. Which of the following is a property of amphiprotic substances?

• A. React with acids only
• B. React with bases only
• C. Can act as both acids and bases
• D. Are inert in chemical reactions

Correct answer: C

Rationale: Amphiprotic substances can donate or accept a proton, so they can act as both acids and bases. The other choices do not accurately describe amphiprotic substances.

3. Which of the following numbers is a perfect square?

• A. 10
• B. 12
• C. 15
• D. 16

Correct answer: D

Rationale: A perfect square is a number obtained by squaring an integer. 16 is the result of squaring 4 (4 x 4 = 16). The other answer choices are not the product of squaring any whole number.

4. What is the process of converting ammonia, a byproduct of protein digestion, into a less toxic form?

• A. Deamination
• B. Transamination
• C. Decarboxylation
• D. Hydrolysis

Correct answer: A

Rationale: Rationale: Deamination is the process of removing an amino group from a molecule, such as converting ammonia (NH3) into a less toxic form like urea. Ammonia is a byproduct of protein digestion and needs to be converted into a less toxic form to be excreted from the body. Deamination is a key step in this process, which occurs mainly in the liver through the urea cycle. Transamination involves the transfer of an amino group from one molecule to another, not the removal of an amino group as in deamination. Decarboxylation is the removal of a carboxyl group from a molecule, and hydrolysis is the breakdown of a compound by adding water.

5. What property of a substance remains constant regardless of the amount of the substance present?

• A. Mass
• B. Weight
• C. Density
• D. Volume

Correct answer: c

Rationale: Density remains constant for a specific substance regardless of the quantity present. It's the mass per unit volume and remains the same for a substance.

6. What is the name of the microscopic finger-like projections that increase the surface area for absorption in the small intestine?

• A. Goblet cells
• B. Paneth cells
• C. Villi
• D. Crypts of Lieberkühn

Correct answer: C

Rationale: Rationale: A) Goblet cells: Goblet cells are specialized cells that secrete mucus to protect the lining of the digestive tract. While important for maintaining the health of the intestines, goblet cells do not increase the surface area for absorption in the small intestine. B) Paneth cells: Paneth cells are specialized cells found in the small intestine that secrete antimicrobial peptides. They play a role in protecting the intestinal stem cells and maintaining the gut microbiota balance, but they do not increase the surface area for absorption. C) Villi: Villi are microscopic finger-like projections found in the small intestine that increase the surface area available for absorption of nutrients. Each villus contains blood vessels and lacteals (lymphatic vessels) that help absorb nutrients from digested food. D) Crypts of Lieberkühn: Crypts of Lieberkühn are small pits located between the villi

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