Membranes and membrane transport

Lecture 7

What is a biological membrane?

An enclosing or separating tissue which acts as a barrier within or around a cell

What is the main component of most membranes?

A lipid bilayer composed of a double layer of phospholipids with proteins embedded in it

What is selective permeability?

The ability of the membrane to allow certain molecules to cross it depending on their size, charge or chemical properties

What is simple diffusion?

Passive movement of small molecules directly across the membrane down a concentration gradient.