Warm-Up #2 10/30/12 1) What does this picture represent? 2) What does hydrophilic mean? Hydrophobic? 3) What does selective permeability mean? 4) Where is the membrane in this picture? What type of cell is it? 5) What is your quiz on tomorrow?

Cell Membrane Unit 4 Biological Membranes

Objective Essential Question TSW understand the function of the cell membrane. TSW differentiate between the structures of the membrane and their function. Why is the cell membrane also called the Fluid Mosaic Model?

Cell Membrane The cell membrane is also known (AKA) the : Plasma Membrane Fluid Mosaic Model

Cell Membrane Regulates what enters and leaves the cell Provides protection Provides support Helps the immune system

Cell Membrane is Made of a lipid bilayer (2 layers) A Flexible barrier It Contains phospholipids proteins carbohydrates cholesterol

Phospholipids (Lipid Bilayer) Phospholipids ( head and tail) Head Water Loving = Hydrophilic Glycerol + Phosphate group Tail Water Fearing = Hydrophobic 2 Fatty Acid chains

Proteins Help move materials across cell membrane Embedded or stuck in membrane Forms channels and pumps

Carbohydrates On the surface or top Act as markers or identifiers Involved in cell recognition

Cholesterol Found in the middle of the bilayer More cholesterol the more rigid the membrane is.

Fluid Mosaic Model Why is it called the Fluid Mosaic Model? Fluid means the molecules of the membrane can move around in the membrane (bilayer) Mosaic means many different types of molecules.

Cell membranes are selectively permeable. –Large molecules like glucose can be blocked or allowed through, depending on cell needs –Small molecules like O 2, CO 2, and H 2 0 can pass through the bilayer (Membrane). Permeability (Regulation)

Cell Wall Provides support and protection for plants, algae, fungi and many prokaryotic cells. Made of cellulose in plant cells Main component of wood and paper Most cell walls are made from carbohydrate and protein fibers

Membrane Drawing On the back of your notes, draw the cell membrane, including the parts we talked about today. Color and Label your drawing. Phospholipids Carbohydrates Proteins Cholesterol

Remainder of Class Today Finish your Unit 4 vocab list for tomorrows quiz Begin working on the Cell Membrane Worksheet from yesterday – Due Tomorrow

Warm-Up #1 10/29/12 1) What are the two types of outer layers a cell can have? - Cell membrane or a Cell wall 2) What is the difference between these two outer layers? - One is on a plant and animal, one is strictly on a plant 3) What is the outer layer of an animal cell made of? - Lipids 4) What is the outer layer of a plant cell made of? - Carbohydrates