Nursing Elites

1. What happens when a protein unfolds?

• A. Activation
• B. Denaturation
• C. Renaturation
• D. Folding

Correct answer: B

Rationale: Rationale: - Activation (Option A) refers to the process of initiating or increasing the activity of a molecule, such as an enzyme. Protein unfolding does not involve activation. - Denaturation (Option B) is the correct answer. Denaturation refers to the process by which a protein loses its three-dimensional structure, leading to the disruption of its function. This can be caused by factors such as heat, pH changes, or chemicals. - Renaturation (Option C) is the process by which a denatured protein regains its native structure and function. Protein unfolding is the opposite of renaturation. - Folding (Option D) is the process by which a protein assumes its functional three-dimensional structure. Unfolding is the reverse process of folding, not folding itself.

2. Which of the following is NOT a property of a catalyst?

• A. Increases the rate of a reaction
• B. Remains unchanged after the reaction
• C. Lowers the activation energy
• D. Creates new products

Correct answer: D

Rationale: A catalyst is a substance that increases the rate of a chemical reaction without being consumed in the process. It remains unchanged after the reaction, which eliminates option B. A catalyst works by lowering the activation energy required for the reaction to occur, which eliminates option C. A catalyst does not create new products in a reaction; it only facilitates the conversion of reactants into products more efficiently. Therefore, option D is NOT a property of a catalyst.

3. The number of protons in an atom is determined by its:

• A. Atomic mass
• B. Electron configuration
• C. Chemical properties
• D. Atomic number

Correct answer: C

Rationale: Atomic number is a fundamental property of an element and is independent of its mass, electron configuration, or chemical behavior.

4. Adipose tissue, commonly known as fat, primarily functions in:

• A. Support
• B. Insulation
• C. Energy storage
• D. All of the above

Correct answer: D

Rationale: The correct answer is D, 'All of the above.' Adipose tissue, or fat, serves multiple functions in the body. It provides support by cushioning and protecting organs, acts as an insulation layer to maintain body temperature, and serves as a crucial energy storage site where excess energy is stored in the form of triglycerides. Therefore, all of the options listed (support, insulation, and energy storage) are accurate functions of adipose tissue.

5. What are the two main types of nuclear decay, and what differentiates them?

• A. Fission and fusion, based on the size of the nucleus
• B. Alpha and beta decay, based on the emitted particle.
• C. Spontaneous and induced decay, based on the trigger.
• D. Isotope decay and chain reactions, based on the stability of the nucleus.

Correct answer: B

Rationale: The two main types of nuclear decay are alpha and beta decay, based on the emitted particle. In alpha decay, an alpha particle (which consists of two protons and two neutrons) is emitted from the nucleus. In beta decay, a beta particle (either an electron or a positron) is emitted from the nucleus. These types of decay are differentiated by the particles they emit, rather than the size of the nucleus, trigger, or stability of the nucleus.

6. What is the acceleration of an object moving at a constant speed of 20 m/s if it comes to a complete stop within 5 seconds?

• A. 0 m/s² (no acceleration)
• B. 4 m/s²
• C. -4 m/s²
• D. Information insufficient

Correct answer: C

Rationale: The acceleration can be calculated using the formula: acceleration = (final velocity - initial velocity) / time. In this case, the final velocity is 0 m/s (as the object comes to a complete stop), the initial velocity is 20 m/s, and the time taken is 5 seconds. Plugging these values into the formula, we get acceleration = (0 m/s - 20 m/s) / 5 s = -20 m/s / 5 s = -4 m/s². Therefore, the acceleration is -4 m/s².

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