Plasma Membrane Proteins

Plasma membrane and organelle membranes have unique proteins which are?

• red blood cells (RBC) plasma membrane contains 50+ types of proteins

• membrane proteins determine most of the membranes functions

Channel Proteins

• involved in the passage of molecules through the membrane

• have a channel that allows a substance to simply move across the membrane

• chloride ion channel (Cl-) - faulty in cystic fibrosis

• results in a think mucus collecting in the airways and in pancreatic and liver ducts

Normal CFTR Channel

moves chloride ions to the outside of the cell

Mutant CFTR Channel

does not move chloride ions, causing sticky mucus to build up on the outside of the cell

Channel protein

allows a particular molecule to cross membrane freely e.g. Cl- channels