THE CELL MEMBRANE Przeworski AKA. THESE NOTES ARE A BIT LONGER BUT YOU HAVE A QUIZ NEXT WEEK AND I WANT YOU TO BE READY.

Functions of The Cell Membrane - Regulates what enters and exits the cell (homeostasis) - Gives a cell shape and support

HOMEOSTASIS The process of maintaining a stable internal environment Example: Air Conditioning, Sweating

Fatty acid The Phospholipid Bilayer - Cell membranes are made of phospholipids

The Phospholipid Bilayer - Phospholipids have a hydrophilic head and a hydrophobic tail

The Phospholipid Bilayer

- The membrane is selectively permeable: it allows only certain molecules to pass through - Some very small molecules can pass directly between the phospholipids - CO 2 -O2-O2 -H2O-H2O The Phospholipid Bilayer

- Large or charged molecules must pass through transport proteins - 3 types: - Channel - Carrier - Pump The Phospholipid Bilayer ChannelCarrier Pump

The Fluid Mosaic Model - The lipid bilayer is described as a fluid mosaic: - Fluid – components of the two layers can move side to side freely - Mosaic – pattern created by scattered proteins embedded in lipid bilayer (chocolate chip cookie)

Other Components - Glycoproteins (keys): help cells recognize other cells with attached carbohydrate chains

Other Components - Cholesterol: found only in animal cell membranes, helps maintain fluidity

VIDEO

Solutes, Solvents, and Solutions Solute: Substance that dissolves in the solvent Solvent: Substance in which the solute dissolves Solution: Mixture of 2 or more substances

More Simply… Solute + Solvent = Solution Solutes are usually solids/powders Solvents are usually liquids

15 A few more examples … Gatorade (Powder, water) Coffee (Sugar, coffee) Saltwater (Salt, water)

TYPES OF SOLUTIONS Isotonic A solution with a solute concentration that is equal to the solute concentration inside a cell.

TYPES OF SOLUTIONS Hypertonic A solution with a solute concentration that is higher than the solute concentration inside a cell

TYPES OF SOLUTIONS Hypotonic A solution with a solute concentration that is lower than the solute concentration inside a cell

POSTER PROJECT (DUE TODAY!) 1= Hypertonic, Hypotonic, Isotonic 2= Solute, Solvent, Solution Make a poster that shows the difference between the three terms. Include a picture, explanation, and color! You can do a meme, comic, or poster. Be creative! When you finish, get a grade check sheet and turn both in!

BUILD A MEMBRANE - Hydrophilic heads: Yellow - Hydrophobic tails: Orange - Channel protein: Red - Transport protein: Blue - Receptor protein: Green - Anchored protein and tethered protein: Purple