Question

Which of the following would NOT diffuse through the plasma membrane by means of simple diffusion?

1 oxygen
2 glucose
3 a steroid hormone
4 a lipid soluble vitamin

Answer 1

Glucose

Glucose, a small polar solute, uses a membrane transporter (a protein carrier) to cross the plasma membrane via facilitated diffusion. In simple diffusion, small nonpolar and lipid-soluble substances (including gases) diffuse directly through the lipid bilayer.