Cells A and B are the same size, shape, and temperature, but cell A is metabolically less active than cell B, and cell B is actively converting oxygen to water in cellular respiration. Oxygen will diffuse more rapidly into cell __________ because __________.

• A. A; the concentration gradient there is shallower
• B. A; its membrane transport proteins will not be saturated
• C. B; the oxygen molecules inside cell B have a higher kinetic energy
• D. B; the gradient of oxygen is oriented in the opposite direction compared to cell A
• E. B; the diffusion gradient in cell B is steeper

Answer: (E)

Verified step by step guidance

1. Understand the concept of diffusion: Diffusion is the movement of molecules from an area of higher concentration to an area of lower concentration. The rate of diffusion is influenced by the concentration gradient, which is the difference in concentration between two areas.
2. Consider the metabolic activity of the cells: Cell B is more metabolically active and is actively converting oxygen to water during cellular respiration. This means that the concentration of oxygen inside cell B is lower compared to cell A, which is less metabolically active.
3. Analyze the concentration gradient: Since cell B is using oxygen more rapidly, the concentration gradient for oxygen between the outside and inside of cell B is steeper than that of cell A. A steeper gradient means a greater difference in concentration, which leads to faster diffusion.
4. Evaluate the options: The correct answer is based on the principle that a steeper concentration gradient results in faster diffusion. Therefore, oxygen will diffuse more rapidly into cell B because the diffusion gradient in cell B is steeper.
5. Conclude the reasoning: The steep concentration gradient in cell B, due to its higher metabolic activity, facilitates a faster rate of oxygen diffusion compared to cell A.