1. Cell Membrane notes

2. Function
Selectively permeable (only allows some substances/materials into cell) barrier separating inside of cell (cytoplasm) from outside environment

3. Fluid Mosaic Model
“fluid” because phospholipids can move laterally (side to side)
“mosaic” because integral and peripheral proteins are scattered throughout the membrane

4. Phospholipids
Form the cell membrane as a bilayer (2 layers) with the hydrophilic (water-loving) phosphate heads facing inside and outside the cell, while hydrophobic (water- fearing) fatty acid tails are between the head, protected from the water inside and outside the cell.

5. Membrane proteins Determine the membrane’s functions
Integral proteins
Peripheral proteins
span distance of the phospholipid bilayer.
Serve as transport proteins, chemical receptors, enzymes, and regulators of cell-to-cell recognition, cell connections, and attachment sites for cytoskeleton
Loosely attached to surface of the membrane

6. Transport proteins cholesterol Carbohydrate
Keeps phospholipids from moving and helps keep them spaced apart.
Helps maintain fluidity of membrane
function in cell recognition, cell signaling, and cell adhesion
Glycoprotein – carb bonded to a protein
Glycolipid – carb bonded to a lipid