Question

Which of the following will double the permeability of a solute in a lipid bilayer?

1) Doubling the molecular radius of the solute
2) Doubling the oil/water partition coefficient of the solute
3) Doubling the thickness of the bilayer
4) Doubling the concentration difference of the solute across the bilayer

Answer 1

Doubling the concentration difference of the solute across the bilayer will double the permeability of the solute in a lipid bilayer. Hence, option 4) is correct.

Step-by-step explanation:

The option that will double the permeability of a solute in a lipid bilayer is doubling the concentration difference of the solute across the bilayer. The concentration difference of a solute across a lipid bilayer drives the diffusion process. The greater the concentration difference, the faster the solute will diffuse through the bilayer.

For example, if there is a higher concentration of a solute on one side of the bilayer compared to the other side, the solute will tend to move from the higher concentration side to the lower concentration side, resulting in an increased permeability of the solute.