Nursing Elites

1. Physical factors such as temperature and pH can alter enzyme activity because they have an effect on the enzyme's ___________.

• A. acidity
• B. shape
• C. chemistry
• D. substrate

Correct answer: B

Rationale: Physical factors such as temperature and pH can alter enzyme activity by affecting the enzyme's shape. Enzymes rely on their specific shapes to function properly and catalyze reactions. Any changes in temperature or pH can disrupt these shapes, causing the enzyme to become denatured and lose its functionality. Therefore, alterations in temperature and pH can impact enzyme activity by directly affecting their shapes. Choices A, C, and D are incorrect because while pH can affect acidity and chemical properties of the enzyme, and temperature can influence the enzyme-substrate interaction, the primary reason for enzyme activity alteration due to temperature and pH is the change in the enzyme's shape.

2. Where is the slide typically placed on a microscope?

• A. Eyepiece
• B. Stage
• C. Focus knob
• D. Objective lens

Correct answer: B

Rationale: The slide is typically placed on the stage of a microscope. The stage is the platform where the slide containing the specimen is positioned for viewing. The eyepiece is where you look through to view the specimen, the focus knob is used to sharpen the image, and the objective lens is responsible for magnification. Therefore, the correct answer is the stage.

3. What is represented by this formula: 6CO₂ + 6H₂O → C₆H₁₂O₆ + 6O₂?

• A. Glycolysis
• B. Cellular respiration
• C. Photosynthesis
• D. Electronic transport

Correct answer: C

Rationale: The formula represents the process of photosynthesis, where carbon dioxide (CO₂) and water (H₂O) are converted into glucose (C₆H₁₂O₆) and oxygen (O₂) using light energy. This process is essential for plants and some microorganisms to produce food and oxygen. Glycolysis and cellular respiration involve breaking down glucose to produce energy, and the electron transport chain is part of cellular respiration, not photosynthesis.

4. What is the magnification of an ocular lens on a microscope?

• A. 4x
• B. 10x
• C. 40x
• D. 100x

Correct answer: B

Rationale: The magnification of an ocular lens on a microscope is typically 10x, which is considered standard for most microscopes. Ocular lenses are designed to magnify the image produced by the objective lens further. Choices A, C, and D are incorrect because they do not represent the standard magnification of an ocular lens. A magnification of 4x, 40x, or 100x would not be typical for an ocular lens in a microscope.

5. Which names a final step in protein synthesis?

• A. DNA unzips.
• B. Amino acids bond.
• C. Transfer RNA bonds to messenger RNA.
• D. Messenger RNA moves to ribosomes.

Correct answer: B

Rationale: The final step in protein synthesis is when amino acids bond together to form a protein chain. This process occurs during translation, where transfer RNA (tRNA) brings specific amino acids to the ribosome, and the ribosome catalyzes the formation of peptide bonds between the amino acids. This step ultimately leads to the synthesis of a complete protein based on the instructions from messenger RNA (mRNA). Choice A ('DNA unzips') is incorrect as it refers to the initiation of transcription, not the final step of protein synthesis. Choice C ('Transfer RNA bonds to messenger RNA') is incorrect as it describes the process of translation initiation rather than the final step. Choice D ('Messenger RNA moves to ribosomes') is also incorrect as mRNA is already present at the ribosomes throughout the translation process, not just in the final step.

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