Nursing Elites

1. What enzymes do lysosomes contain, leading to their nickname as the cell's 'suicide bags'?

• A. Hydrolytic enzymes
• B. Ligases (bonding enzymes)
• C. Transferases (molecule transfer)
• D. Oxidoreductases (redox reactions)

Correct answer: A

Rationale: Lysosomes are organelles filled with hydrolytic enzymes that break down proteins, nucleic acids, lipids, and carbohydrates. These enzymes aid in digesting cellular waste and foreign substances, hence the term 'suicide bags' due to their involvement in cell degradation and recycling. Ligases are enzymes that catalyze the joining of two large molecules by forming a new chemical bond, not present in lysosomes. Transferases are enzymes that catalyze the transfer of functional groups from one molecule to another, not found in lysosomes. Oxidoreductases are enzymes involved in oxidation-reduction reactions, which are not the primary function of lysosomes.

2. What is the basic structure of an atom?

• A. Protons, neutrons, electrons
• B. Protons, electrons, ions
• C. Neutrons, electrons, ions
• D. Protons, ions, molecules

Correct answer: A

Rationale: The basic structure of an atom consists of protons and neutrons located in the nucleus, with electrons orbiting around the nucleus in specific energy levels or shells. Protons carry a positive charge, neutrons carry no charge, and electrons carry a negative charge. This arrangement maintains the overall neutrality of the atom, with the number of protons equaling the number of electrons. Therefore, the correct answer is 'Protons, neutrons, electrons.' Choices B, C, and D are incorrect as they do not accurately represent the fundamental components of an atom. Choice B includes 'ions,' which are charged particles, not fundamental components of an atom. Choice C includes 'ions' and lacks protons. Choice D includes 'ions' and 'molecules,' which are not part of the basic structure of an atom.

3. How does the body maintain a relatively constant blood pH level, even with changes in blood carbon dioxide concentration?

• A. Cellular respiration
• B. Gas exchange
• C. Buffering system
• D. Deoxygenation

Correct answer: C

Rationale: The correct answer is C: Buffering system. The buffering system is responsible for maintaining a relatively constant blood pH level by minimizing changes in pH when acids or bases are added to the blood. This system consists of chemical compounds that can donate or accept protons to help stabilize the pH. Choice A, Cellular respiration, and Choice B, Gas exchange, are processes involved in gas exchange within the body, not specifically related to maintaining blood pH. Choice D, Deoxygenation, refers to the removal of oxygen from a substance and is not directly related to the regulation of blood pH.

4. What is the process called in which a substance changes from a gas to a liquid?

• A. Condensation.
• B. Evaporation.
• C. Sublimation.
• D. Vaporization.

Correct answer: A

Rationale: Condensation is indeed the correct answer. It is the process by which a substance changes from a gas to a liquid. This occurs when the temperature of a gas decreases enough for its particles to lose energy and come together to form a liquid. On the other hand, evaporation is the process of a liquid changing to a gas. Sublimation is the direct transition of a substance from a solid to a gas without passing through the liquid phase. Vaporization, on the other hand, is the general term for the process of a liquid changing to a gas, which includes both evaporation and boiling.

5. The van't Hoff factor (i) accounts for the number of particles a solute dissociates into in solution. For a compound that dissociates completely in water, i would be...

• A. 0
• B. Less than 1
• C. 1
• D. More than 1

Correct answer: D

Rationale: The van't Hoff factor (i) represents the number of particles a solute dissociates into in solution. For a compound that dissociates completely in water, i would be more than 1 because it breaks apart into more particles than the original compound. This is due to complete dissociation leading to an increase in the number of particles in solution, resulting in i being greater than 1. Choice A is incorrect as a compound that dissociates completely will not have an i value of 0. Choice B is incorrect because when a compound dissociates completely, the van't Hoff factor is not less than 1. Choice C is incorrect as a compound that dissociates completely will not have an i value of 1, but rather more than 1 due to the increased number of particles in solution.

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