Name: ______________________________________________________________ Period: _____________________ 7.2 The Plasma Membrane What is the Plasma Membrane? The plasma membrane is a ________ , ____________ and ________________________ boundary between a cell and its surroundings Selective Permeability: _______________________________________________________ ________________________________________________________________________ ____ Selective Permeability Example What types of sports ball would fit through a chain link fence? What types wouldn’t? o Would fit: _____________________________________________________________ o Would not fit: __________________________________________________________ o Think: What do the balls that will fit through the fence have in common? __________________________________________________________________ ____ Think back to the bubble lab, what would go through the bubble? How did we get around the bubble’s semi-permeability later in the lab? ________________________________________________________________________ ________________________________________________________________________ ________ Homeostasis The main job of the plasma membrane (or cell membrane) is to help the body maintain ___________________ Video Notes (What is homeostasis?): _____________________________________ _______________________________________________________________________ A Connection to Biochemistry (Ch 6) The plasma membrane is made up of a _______________________________________ o What does that mean? ________________________________________________ o Reminder: A lipid is a molecule that contains a phosphate-group and two fatty acid chains. Draw one here → The Phospholipid Bilayer _________ layers of phospholipids that are arranged _________ ____ __________ this allows the membrane to exist in ___________ environments A phospholipid has 2 main parts, a ______________________ Head (Polar, charged) and a ____________________ Tail (Nonpolar, no charge) Describe the benefit of the bilayer structure of the plasma membrane ____________ ________________________________________________________________________ ____ Other Parts of the Plasma Membrane Cholesterol (structure), Proteins (many functions), Carbohydrates (structure) _________________- special proteins that transmit signals to the inside of the cell o Like a microscopic satellite ________________ Proteins- Used to move substances and waste in and out of the cell (these contribute to the semi-permeability of the membrane) The Fluid Mosaic Model Describe the fluid mosaic model in your own words: _______________________________ ________________________________________________________________________ ____ ________________________________________________________________________ ____