If oxygen is more concentrated outside a cell than inside, what will most likely happen to the oxygen molecules?

• A. Oxygen will remain stationary and not move across the membrane.
• B. Oxygen will diffuse out of the cell.
• C. Oxygen will be actively transported out of the cell.
• D. Oxygen will diffuse into the cell.

Answer: (D)

Verified step by step guidance

1. Understand the concept of diffusion: Diffusion is the passive movement of molecules from an area of higher concentration to an area of lower concentration, driven by the concentration gradient, without requiring energy input.
2. Identify the concentration gradient: In this scenario, oxygen is more concentrated outside the cell than inside, creating a concentration gradient that favors the movement of oxygen molecules into the cell.
3. Recognize the type of transport: Since oxygen is a small, nonpolar molecule, it can easily pass through the lipid bilayer of the cell membrane via simple diffusion, without the need for active transport or energy expenditure.
4. Eliminate incorrect options: Oxygen will not remain stationary because diffusion occurs naturally due to the concentration gradient. Oxygen will not diffuse out of the cell because the concentration is higher outside. Active transport is not required because diffusion is passive.
5. Conclude the most likely outcome: Based on the principles of diffusion and the concentration gradient, oxygen molecules will diffuse into the cell until equilibrium is reached.