The Plasma Membrane

What is it? Different names: Plasma Membrane Cell Membrane Lipid Bilayer Semi-permeable Membrane All of these mean the same part of the cell. It has many important functions.

What it Looks Like Phospholipid bodies Hydrophilic Head Hydrophobic tails.

Functions Protection Sets up the cell boundaries. Signaling Keeps some out and some in. Sets up the cell boundaries. Signaling Two types of transport Active Passive

Protection What you think it is. Prevent the bacteria and viruses. Semi-permeable Only allows certain amounts to come in. Also, maintains homeostasis.

Cell Boundaries Like your projects said. This is the limit of the cell. Keeps the organelles covered. Helps keep pH stable.

Signaling Membrane has proteins This also is for cell communication These can tell the cell is dying This also get what cell needs. This also is for cell communication Proteins will link and cells can talk Signals get passed along.

Types of Transport Active vs. Passive Passive Active Active requires energy Passive does not. Passive Diffusion Osmosis Active Require ATP Can be joint transport.

Diffusion Just goes in and out without any assistance Does not need a protein to help. No energy. Like the door when it is open.

Osmosis This is diffusion of water. Only water can do this. It can pass through the membrane without working Salt water vs. fresh water in a beaker.

Active Transport ATP can cause the membrane to switch. The protein will change between open to the outside to open on the inside. Can be done with multiple types as well. Ca- K+ ion pump Can be a switching pump. Opens to the inside and then the outside.