Adaptations for Rapid Transport

Question 1

The rate at which diffusion (including both simple diffusion and facilitated diffusion) occurs across external and internal cell membranes varies

Some cells are adapted for rapid transport (diffusion) of molecules across their internal or external membranes

The rate of diffusion depends on several factors. These include

Answer 1

Temperature

The surface area of the exchange surface

The concentration gradient across the exchange surface

The thickness of the exchange surface

Question 2

Simple diffusion
The rate of simple diffusion depends on three main factors:

Answer 2

surface area

Concentration gradient

thickness of exchange surface

Question 3

facilitated diffusion depends on

Answer 3

Number of channel or carrier proteins available in exchange surface