CELL MEMBRANE

 ALL CELLS!!!  Prokaryotes  (bacteria, archaea)  Eukaryotes  (plants, animals, protists, fungi) WHAT TYPES OF CELLS HAVE CELL MEMBRANES?

Maintain in two ways: WHAT IS THE FUNCTION OF THE CELL MEMBRANE?

Maintain HOMEOSTASIS in two ways: 1.Protecting and containing what’s inside the cell 2.Regulating the movement of materials in/out of the cell  Homeostasis – Maintain a relatively constant internal environment (inside the cell) WHAT IS THE FUNCTION OF THE CELL MEMBRANE?

 It needs to be flexible, and allow only certain materials to pass through it.  Selective Permeability: (a.k.a. semi-permeable) some materials are “selected” to pass through while others are not. WHAT DOES THIS TELL YOU ABOUT THE STRUCTURE OF THE CELL MEMBRANE?

Window Screen Selectively permeable Some things pass through (air, water, dust, etc.) Big things cannot (insects, leaves, etc.) Window Glass Impermeable Nothing passes through ONE WAY TO THINK OF SELECTIVE PERMEABILITY… VS.

VOCABULARY Hydrophilic: Hydrophobic: Phosphate Head Fatty Acid Tails

VOCABULARY Hydrophilic: water “loving” Turns toward the water Hydrophobic: water “fearing” “Hides” from the water inside/outside the cell Phosphate Head Fatty Acid Tails

 Plasma Membrane: Same as “cell membrane”  Fluid Mosaic:  Mosaic – the membrane is made of many different molecules (like a colourful mosaic)  Fluid – the molecules can move around within the membrane VOCABULARY

STRUCTURE: PARTS OF THE CELL MEMBRANE MoleculeFunction/DescriptionColour Phosphate Head Attracts water (water “loving”) Repel water (water “fearing”)  Help identify the cell to other cells (cell “ID tag”) Transport materials across the membrane (tunnels/pumps) Communicate with other cells Makes sure the membrane is flexible, but not TOO flexible

STRUCTURE: PARTS OF THE CELL MEMBRANE MoleculeFunction/DescriptionColour Phosphate Head Attracts water (water “loving”) Lipid tails Repel water (water “fearing”)  Help identify the cell to other cells (cell “ID tag”) Transport materials across the membrane (tunnels/pumps) Communicate with other cells Makes sure the membrane is flexible, but not TOO flexible

STRUCTURE: PARTS OF THE CELL MEMBRANE MoleculeFunction/DescriptionColour Phosphate Head Attracts water (water “loving”) Lipid tails Repel water (water “fearing”)  Carbohydrate chains Help identify the cell to other cells (cell “ID tag”) Transport materials across the membrane (tunnels/pumps) Communicate with other cells Makes sure the membrane is flexible, but not TOO flexible

STRUCTURE: PARTS OF THE CELL MEMBRANE MoleculeFunction/DescriptionColour Phosphate Head Attracts water (water “loving”) Lipid tails Repel water (water “fearing”)  Carbohydrate chains Help identify the cell to other cells (cell “ID tag”) Membrane proteins Transport materials across the membrane (tunnels/pumps) Communicate with other cells Makes sure the membrane is flexible, but not TOO flexible

STRUCTURE: PARTS OF THE CELL MEMBRANE MoleculeFunction/DescriptionColour Phosphate Head Attracts water (water “loving”) Lipid tails Repel water (water “fearing”)  Carbohydrate chains Help identify the cell to other cells (cell “ID tag”) Membrane proteins Transport materials across the membrane (tunnels/pumps) Communicate with other cells Cholesterol Makes sure the membrane is flexible, but not TOO flexible

REMEMBER

REMEMBER STRUCTURE DETERMINES FUNCTION

TIME TO DRAW THE CELL MEMBRANE!