Which of the following methods of transport across a membrane does not require a protein?

Question

Quizplus · Accepted Answer

Simple diffusion does not require a protein to transport molecules across the membrane. It occurs when small, non-polar molecules pass directly through the lipid bilayer of the membrane from an area of high concentration to an area of low concentration. Passive transport refers to any transport of molecules across the membrane without using energy, so it includes simple diffusion but also includes facilitated transport, which does require a protein. Active transport always requires a protein to move molecules against their concentration gradient.

Which of the Following Methods of Transport Across a Membrane