Cells a and b are the same size and shape, but cell a is metabolically quiet and cell b is actively consuming oxygen. oxygen will diffuse more quickly into cell because cells a and b are the same size and shape, but cell a is metabolically quiet and cell b is actively consuming oxygen. oxygen will diffuse more quickly into cell because the oxygen molecules inside cell b have a higher kinetic energy its membrane transport proteins will not be saturated the diffusion gradient there is shallower the diffusion gradient there is steeper

Oxygen will diffuse more quickly into cell B because the diffusion gradient there is steeper.  

The concentration gradient depicts the slow change in the concentration of solutes found in a solution between the two regions. A gradient in biological terms arises due to an unequal distribution of ions across the membrane of the cell. Both the process of facilitated and simple diffusion take place when there is a concentration gradient.  

the relative standard reduction potential of the half-cell in which reduction occurs; more positive than the other half-cell. reduction is a chemical process in which electrons are added to an atom or an ion; it always occurs accompanied by oxidation of the reducing agent.