fluid mosaic model

2.4 - different functions of different protein molecules found in the cell membrane

function of channel proteins

channel proteins allow the passage of specific ions and molecules across the membrane

function of carrier proteins

carrier proteins allow the passage of specific ions and molecules across the membrane

functions of enzymes

enzymes catalyse reactions

functions of receptors

receptors have specific binding sites, allowing chemical messengers to bind to the protein, resulting in the relay of message to the inside of the cell

function of glycoproteins

glycoproteins play a role in cell-cell recognition and cell adhesion, they consist of carbohydrate chained covalently bonded to proteins and they are found on the side of the membrane facing the exterior of the cell

functions of glycolipids

glycolipids consist of carbohydrate molecules covalently bonded to phospholipid molecules, the carbohydrate molecules are attached to the side of the membrane facing the exterior of the cell, they are involved in cell recognition

function of cholesterol

cholesterol plays a role in reducing fluidity of the cell membrane