Chapter 3

Plasma membrane

Has 3 macromolecule types (Phospholipid, Proteins, Carbohydrate)

Phospholipid

Molecules that form a flexible bilayer, fluid like the sea

Protein

Embedded in the plasma membrane, some move, some are anchored in place

Carbohydrate

Act as cell identification tags on surface of plasma membrane

The membrane is fluid mosaic

Fluid = movement of membrane components

Mosaic = large items like proteins are visible

Lipids of plasma membrane

Formed by phospholipid bilayer and has a amphipathic structure

Selective permeability

Cell membrane is picky about what gets through

Cell membrane with high permeability

Small, nonpolar, uncharged, hydrophobic solutes

Cell membrane with moderate permeability

Small, uncharged, hydrophilic

Cell membrane with very low to no permeability

Large proteins, hydrophilic, small, charged

Cholesteral

A lipid found in both layers of the membrane. Is hydrophilic and a fluidity buffer.

Fluidity buffer

How fast membrane components move. Can be affected by temperature

Proteins of the cell membrane

Integral membrane proteins and Peripheral proteins

Integral membrane proteins

Embedded in the membranes and are amphipathic

Peripheral proteins

On the surface of the cell membrane.

Carbohydrates of Plasma membrane

Glycocalyx: found on the exterior layer of the bilayer.

Molecules containing carbohydrates

Glycoprotein and glycolipid