1. The Cell Membrane

2. Homeostasis – Maintaining a balance
Living organisms must adjust to their environment
Cells must keep the proper concentration of things inside the cell

3. Structure of the Cell (or plasma) Membrane
Phospholipid Bilayer – two sheets of phospholipids
Found all around the cell and all of its organelles
Embedded with proteins and strengthened with cholesterol molecules

4. What’s a phospholipid?

5. Selective Permeability
Allowing some materials to pass through while keeping others out
‘semi-permeable’ membrane
Maintains balance
Keeping in water and glucose
Eliminating wastes and CO2

6. Membrane Proteins
Determine what particles can pass through the membrane
Serve as enzymes (speed up reactions)
Two types
Protein Channel = tunnel
Carrier Protein = gate

7. Fluid Mosaic
Membrane is made up of lots of moving parts that can move freely within the membrane