Anatomy and Physiology

1. Anatomy and Physiology Cell Transport

2. Types of Transport Diffusion • Characteristics • Particles move from an area of high concentration to an area of low concentration. • Moves “down” or “with” the concentration gradient. (difference in concentration) • Does not require energy.

3. Types of Transport • Factors effecting the rate of diffusion • Temperature- as temperature increase, rate of diffusion increases. • Pressure- as pressure increases, rate of diffusion increases. • Steepness of the concentration gradient -the steeper the gradient, the faster the rate of diffusion.

4. Types of Transport • Diffusion will continue until dynamic equilibrium is reached. • Dynamic equilibrium -continuous movement of particles, but no overall concentration change. (Everything is equally distributed).

5. Type of Transport Osmosis • Characteristics • Movement of water across a cell membrane. • Cell has no control over movement of water. It continues to move until [inside] = [outside]. [ ] =concentration

6. AS Biology, Cell membranes and Transport Osmosis CONCENTRATED SOLUTION DILUTE SOLUTION Cell membrane partially permeable. Sugar molecule VERY Low concentrationof water molecules. Outside cell Inside cell VERY High concentration of water molecules.

7. AS Biology, Cell membranes and Transport Osmosis Cell membrane partially permeable. Low conc. of water molecules. OSMOSIS High conc. of water molecules. Outside cell Inside cell

8. AS Biology, Cell membranes and Transport Osmosis Cell membrane partially permeable. OSMOSIS Outside cell Inside cell EQUILIBRIUM. Equal water concentration on each side. Equal water potential has been reached. There is no net movement of water – water moves in and out of cell at the same rate.

9. What is a solution? • 2 Parts: • Solvent – Usually a liquid like water • Solute – Usually a solid such as sugar, salt

10. Osmosis Animations for isotonic, hypertonic, and hypotonic solutions Isotonic Solution Isotonic: The concentration of solutes in the solution is equal to the concentration of solutes inside the cell. ISO = THE SAME Result:Water moves equally in both directions and the cell remains same size! (Dynamic Equilibrium)

11. Osmosis - Types of Solutions Isotonic • [water inside] = [water outside] • Dynamic equilibrium reached immediately. Normal Red blood cells

12. Osmosis Animations for isotonic, hypertonic, and hypotonic solutions Hypotonic Solution Hypotonic: The solution has a lower concentration of solutes and a higher concentration of water than inside the cell. (Low solute (HYPO); High water) Result: Water moves from the solution to inside the cell): Cell Swells and bursts open (cytolysis)!

13. Osmosis - Types of Solutions Hypotonic • [water inside] < [water outside] • Solutes are higher inside the cell. • Water flows in, cell swells. • Cell could burst if water flow continues. Swollen red blood cells

14. Osmosis Animations for isotonic, hypertonic, and hypotonic solutions Hypertonic Solution Hypertonic: The solution has a higher concentration of solutes and a lower concentration of water than inside the cell. (High solute (HYPER); Low water) shrinks Result:Water moves from inside the cell into the solution: Cell shrinks (Plasmolysis)!

15. Osmosis - Types of Solutions Hypertonic • [water inside] > [water outside]. • Solutes are higher outside the cell. • Water leaves the cell, cell shrinks. Dehydrated red blood cells

16. Types of transport Passive vs. Active Transport • Passive - no energy required • Active - energy required

17. Types of Cellular Transport Passive Transport cell doesn’t useenergy Diffusion Facilitated Diffusion Osmosis Active Transport cell does use energy Protein Pumps Endocytosis Exocytosis • Animations of Active Transport & Passive Transport Weeee!!! high low This is gonna be hard work!! high low

18. Types of Transport • Passive Transport • Movement across a membrane by diffusion. • Facilitated diffusion - moves down the concentration gradient with the aid of a protein molecule. • Most glucose moves this way

19. Passive Transport: 2. Facilitated Diffusion A B 2. Facilitated diffusion: diffusion of specific particles through transport/carrier proteins found in the membrane • Transport Proteins are specific – they “select” only certain molecules to cross the membrane • Transports larger or charged molecules Facilitated diffusion(Channel Protein) Diffusion (Lipid Bilayer) • http://bio.winona.edu/berg/Free.htm Carrier Protein

20. Types of Transport • Active Transport • moves from an area of low concentration to an area of high concentration. • Moves up or against the concentration gradient. • Glucose moving from blood stream into liver for storage.

21. Types of Transport • Bulk Transport • Moving large particles across the cell membrane. • Endocytosis - movement • into the cell • Exocytosis - movement out of the cell

22. Cell changes shape – requires energy • EX: Hormones or wastes released from cell

23. Paramecium Contractile vacuole full Contractile vacuole empty

24. Bulk Transport • Endocytosis - 2 types • Pinocytosis- bulk transport of liquids into the cell. • Phagocytosis- “cell eating”- bulk transport of solids into the cell.

25. Cell membrane in-folds around food particle • “cell eating” • forms food vacuole & digests food • This is how white blood cells eat bacteria!