1. Chapter 3Cells Physiology Do you remember learning about? • Membrane Transport • -Passive • -Active

2. Membrane Transport • Movement into and out of cells to maintain HOMEOSTASIS Filtration Fill in as we go

3. Cellular Fluids • Solution • Solvent – dissolving medium (ex. water) • Solutes – what gets dissolved (ex. sugar, salt) • Intracellularfluid • inside cell • Interstitialfluid - outside cell

4. Passive Processes Diffusion • Molecules ALWAYS moving; Brownian motion • Movement from high to low concentration, or down a concentration gradient • Equilibrium - concentration is equal/balanced.

5. Membrane is Selective Permeability • Allows some materials to pass, not all • 3 types of diffusion in cells • Simple diffusion - lipid-soluble or small - to pass through pores • Facilitated diffusion - too big or not lipid-soluble; need protein carriers (channel or gated proteins) • Osmosis - movement of water across membrane from [hi] to [lo]

6. Study the diagram below. It represents a container that is divided by a semi permeable membrane. A different solution in its initial state is shown on each side of the membrane. 1. Which substance(s) can move through the membrane? Why? 2. Which direction will the molecule(s) will move? To side I or II? 3. Which substance will move across fastest? Why? 4. How long will the molecule(s) will continue to move?

7. Osmosis - How Cells Respond to Different Solutions 90% H2O 10% solute 85% H2O 15% solute 95% H2O 5% solute 90% H2O 10% solute 90% H2O 10% solute 90% H2O 10% solute Hypotonic Hypertonic Isotonic (no net movement of water) What solution would you give someone who is retaining water?

8. Why shouldn’t you drink ocean water if you are thirsty?

9. Another Passive Process Filtration • Water & solutes forced through a membrane by pressure • Pressure gradient • (high to low) Happens in kidneys.

10. Active Transport Processes • Transport substances that can’t pass because: • too large • not lipid-soluble • against concentration gradient • 2 common forms of active transport • Solute pumping • Bulk transport Energy (ATP) required!

11. Solute pumping • Amino acids, some sugars and ions are pumped • ATP energizes protein carriers, moves substances againstconcentration gradients (from low to high, or up a gradient concentration. Sodium-Potassium Pumps

12. Bulk Transport Exocytosis • Moves out of cell by vesicle Endocytosis • engulfed by vesicle & brought in • 2 Types • Phagocytosis – cell eating • Pinocytosis – cell drinking

13. Filtration Any direction as needed High to Low Channel or Gate Proteins Pressure through capillaries Protein Pumps Anything dissolved in blood Water, urea, sugars, ions