1. The Cell Membrane Bell-ringer 12-7-15: Make a list of anything you know about the plasma membrane

2. Membrane Function Outer plasma membrane Forms a boundary between a living cell and surroundings (prok and euk cells) Selectively permeable ( Controls traffic of molecules in and out) Cellular recognition Internal organelle membranes Form boundary for the organelles in Eukaryotic cells Compartmentalize chemical reactions

3. Membrane is a collage of proteins & carbohydrates embedded in the fluid matrix of the lipid bilayer Extracellular fluid

4. 1. Phospholipids Fatty acid Phosphate Phosphate head hydrophilic Fatty acid tails hydrophobic Arranged as a bilayer “repelled by water” “attracted to water”

5. Arranged as a Phospholipid bilayer polar hydrophilic heads nonpolar hydrophobic tails polar hydrophilic heads Serves as a cellular barrier / border, creates a ‘sealed area’

6. Plasma Membrane Video

7. 2. Cholesterol Molecules Molecules found throughout the plasma membrane in animal cells, in between fatty acid tails. Helps resist changes in fluidity when the temperature changes. Stabilizes and Strengthens membrane

8. Glycoproteins and glycolipids are short chain carbohydrates attached to proteins and lipids on the extracellular side of the membrane. Glycoproteins and glycolipids are short chain carbohydrates attached to proteins and lipids on the extracellular side of the membrane. These carbohydrate chains act as antennae, receiving chemical messages from other cells. They are also markers & identifiers that identify the cell to other cells. 3. Glycoproteins and Glycolipids

9. Embedded in the bilayer are proteins Most of the membrane’s functions are accomplished by the embedded proteins. Integral proteins implanted in the membrane- partway or all the way across Peripheral proteins are on one side or the other of the membrane

10. Small hydrophobic molecules (without a charge/ nonpolar) pass easily through the membrane past the phospholipids. Like Oxygen and Carbon Dioxide.

11. Polar molecules, ions, and large molecules (hydrophilic) cannot simply pass through. They are moved through by specific transport proteins. Like glucose, water, and ions such as Na⁺ and K⁺.

12. Transport Proteins - Transport hydrophilic/larger materials across the plasma membrane. - Channels Membrane Pumps Carriers

13. 13 Aquaporins Water Channels Proteins used during OSMOSIS Can move 3 Billion molecules per sec WATER MOLECULES

14. Adhesion Proteins

15. Communication Proteins

16. Messenger molecule Activated molecule Receptor Receptor Proteins