Selective permeability It's a term used to describe how cells only allow certain things in and certain thing out. In other words, selective permeability regulates what gets in and what gets out of a cell.
Fluid Mosaic Model
It is said that the fluid mosaic model describes the structure of the plasma membrane, and it's known to giving the membrane a fluid like character. This model includes phospholipids, cholesterol, glycoproteins, glycolipids, and proteins.
Phospholipids- They're fats that float around, and in the fluid mosaic model membranes are composed of phospholipid bilayers with various protein molecules floating around it. They are known to being amphipathic, which is when part of likes water and a part of it hates water. They are also small and uncharged. It means that they only allow small and uncharged particles through it.
Cholestrol- What cholestrol is, is a waxy type of liquid, in other words it's sort of a type of fat. It is one of the major components in the fluid mosaic model. The major role that it plays is that it keeps the phospolipids close enough to each other and keeps them from drifiting apart to quickly.
Glycoprotein- It's made up of proteins and sugar. The role this plays is that carbohydrates attach themselves to glycoprotein.
Glycolipid- It's a type of fat that gets carbohydrates attached to it.
Proteins- They help regulate transport. They allow bigger and charged particles through.