Osmosis

9.1 PLASMA MEMBRANE
I. All cells must maintain homeostasis in order to live.
- they do this by controlling what materials can enter and leave
II. All cells have a plasma membrane that is SELECTIVELY PERMEABLE - this only allows for specific things to enter and leave the cell
A. Selective permeability is achieved by the structure of the plasma membrane (fig.9.3, pg 220)
1. The cell membrane is composed of 2 layers of PHOSPHOLIPIDS -
"phospho" = phosphate "lipid" = fat
· referred to as the "phospholipid bilayer"
· phospholipids have polar, water-soluble heads at…