Question

Which of the following would NOT increase the rate of simple diffusion across the phospholipid bilayer of the plasma membrane?

a) Higher temperature.
b) Larger concentration gradient.
c) Larger molecular size.
d) Shorter distance to travel.

Answer 1

Larger molecular size would not increase the rate of simple diffusion across the phospholipid bilayer of the plasma membrane.

Step-by-step explanation:

Simple diffusion is the passive movement of molecules from an area of higher concentration to an area of lower concentration across a semipermeable membrane, such as the phospholipid bilayer of the plasma membrane. Several factors can affect the rate of simple diffusion, and the question asks which one would NOT increase the rate.

Larger molecular size would NOT increase the rate of simple diffusion because larger molecules have a harder time passing through the phospholipid bilayer. This is because their size prevents them from fitting in between the individual phospholipids that make up the bilayer. On the other hand, higher temperature, larger concentration gradient, and shorter distance to travel would all increase the rate of simple diffusion.