Physics

A typical mammalian cell is a 15-m-diameter sphere with an oxygen partial pressure of 40 mmHg. It is separated from the higher oxygen concentration in blood by a capillary wall with a thickness of 1.0 m. (The much thinner cell-wall thickness can be neglected.) The oxygen partial pressure of blood varies with distance along the capillary, but 75 mmHg is a typical value. The diffusion coefficient of oxygen through the capillary wall is reported to be 1.110^-11 m²/s.

Suppose that 25% of the cell wall is in contact with a capillary, the remaining 75% being in contact with other cells. What is the diffusion rate in molecules/s of oxygen into the cell? Assume a body temperature of 37C.