Nursing Elites

1. Which type of passive transport uses proteins that change shape to move a target molecule through the membrane?

• A. Diffusion
• B. Carrier proteins
• C. Channel proteins
• D. None of the above

Correct answer: B

Rationale: The correct answer is B: Carrier proteins. Carrier proteins are involved in facilitated diffusion, a type of passive transport where specific target molecules are moved across the membrane with the help of proteins that change shape. These carrier proteins bind to the target molecule on one side of the membrane, undergo a conformational change, and then release the molecule on the other side. This process is crucial for the selective transport of certain molecules that cannot pass through the membrane by simple diffusion. Choices A and C are incorrect because diffusion and channel proteins do not involve proteins that change shape to transport target molecules selectively. Choice D is incorrect as carrier proteins fit the description provided in the question.

2. Which is not a product of the Krebs cycle?

• A. ATP
• B. Carbon dioxide
• C. Glucose
• D. NADH

Correct answer: C

Rationale: Glucose is not a direct product of the Krebs cycle. Glucose is a starting molecule that undergoes glycolysis outside the mitochondria to produce pyruvate, which then enters the mitochondrial matrix to participate in the Krebs cycle. The Krebs cycle primarily generates ATP, carbon dioxide, and NADH as products. Choices A, B, and D are all products of the Krebs cycle, making them incorrect answers.

3. Which cellular structure is found in animal cells but not in plant cells?

• A. Centriole
• B. Cytoplasm
• C. Vacuole
• D. Golgi apparatus

Correct answer: A

Rationale: The correct answer is A, Centriole. Centrioles are found in animal cells but not in plant cells. They play a crucial role in organizing microtubules during cell division, aiding in the formation of the mitotic spindle. Plant cells lack centrioles; instead, they utilize microtubule organizing centers to perform similar functions during cell division. Choices B, C, and D are incorrect because cytoplasm is a part of both animal and plant cells, vacuoles are found in plant cells and some animal cells, and the Golgi apparatus is present in both types of cells.

4. Where is the site of cellular respiration in eukaryotic cells?

• A. Nucleus
• B. Chloroplasts
• C. Mitochondria
• D. Ribosomes

Correct answer: C

Rationale: The correct answer is C: Mitochondria. Mitochondria are often referred to as the powerhouse of the cell because they are responsible for cellular respiration in eukaryotic cells. During cellular respiration, mitochondria generate energy in the form of ATP. Choices A, B, and D are incorrect. The nucleus is the organelle that houses the cell's genetic material, chloroplasts are responsible for photosynthesis in plant cells, and ribosomes are involved in protein synthesis, not cellular respiration.

5. What is necessary for active transport through a membrane to take place?

• A. Glucose
• B. Oxygen
• C. Sodium
• D. ATP

Correct answer: D

Rationale: Active transport through a membrane requires energy in the form of ATP (adenosine triphosphate). ATP provides the necessary energy for the transport proteins to move molecules against the concentration gradient, from an area of lower concentration to higher concentration. This process is essential for maintaining cellular functions and regulating the internal environment of a cell. Glucose, oxygen, and sodium are important molecules involved in various cellular processes, but they are not the primary energy source required for active transport across membranes. Therefore, the correct answer is ATP.

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