The Plasma Membrane Who has a plasma membrane

The Plasma Membrane

Who has a plasma membrane? • Prokaryotes and Eukaryotes

Plasma Membrane • Phospholipid bilayer • Made of Phosphorous heads and Lipid tails • 2 layers back to back

Phosphorous • LOVES water = Hydrophilic • It is polar which means it interacts with water

Lipids • There are 2 fatty acid tails • Non-polar, which allows them to repel water • Hydrophobic- scared of water

Whats its function? • It’s how the cell takes in nutrients • It’s how the cell excretes waste • Recognition of chemical signals • It’s selectively permeable, meaning it chooses what will go in and out of the cell

Proteins • Proteins are embedded in the plasma membrane • Some proteins go straight through the membrane • Function: help regulate what goes in and out of the cell • They’re called Transport Proteins • Transport/ Channel/ Carrier Protein

Transport Proteins

Cholesterol • Prevents the plasma membrane’s fatty acid chains from sticking together

Carbohydrates • Carbohydrate chains (CHO) stick out from the cell surface • They act as identifying markers on cells or recognition signals Carbohydrates Chains

Fluid Mosaic Model • The Plasma Membrane is referred to as the Fluid Mosaic Model • It is flexible (fluid) • Its proteins move within the plasma membrane (mosaic)