The document discusses cell membranes and the methods of transport across membranes. It covers four main methods: 1) Diffusion - the passive movement of molecules from high to low concentration without energy. 2) Osmosis - the passive movement of water across membranes. 3) Facilitated diffusion - uses carrier proteins to transport molecules across membranes without energy. 4) Active transport - requires energy (ATP) to transport molecules against their concentration gradient using carrier proteins. The document provides examples and explanations of these transport methods.

1. Cell MembranesOsmosis and Diffusion

2. PREFIX – SUFFIX ADDITIONS Hypo – under, beneath, lacking Hyper – over, above, excess Iso – equal Tonic – stretching, tone

3. Functions of Membranes1. Protect cell2. Control incoming and outgoing substancesMaintain ion concentrations of various substancesFLASH CARD ALERT!!! 4. SELECTIVELY PERMEABLE - allows some molecules in, others are kept out

4. Phospholipid Bilayer

5. Fluid Mosaic Model

6. SolutionsSolutions are made of solute and a solventFLASH CARD ALERT!!!! SOLVENT - the liquid into which the solute is poured and dissolved. We will use water as our solvent in Lab #4SOLUTE - substance that is dissolved or put into the solvent. Salt and sucrose are solutes.

7. Methods of Transport Across Membranes1. Diffusion2. Osmosis3. Facilitated Diffusion4. Active Transport

8. FLASH CARD ALERT!!! 1. DIFFUSION -passive transport of molecules - no energy expended2. OSMOSIS- Passive transport of WATER across membrane3. FACILITATED DIFFUSION- Use of carrier proteins to carry polar molecules or ions across membrane4. ACTIVE TRANSPORT requires energy to transport molecules AGAINST A CONCENTRATION GRADIENT. energy is in the form of ATP

9. Where does that ATP come from?

10. DiffusionMovement of molecules from an area of high concentration to an area of low concentration.DIFFUSION = MOVEMENT OF MOLECULESOSMOSIS = MOVEMENT OF WATER.

11. Diffusion

12. Facilitated Diffusion

13. Passive – Does not require energy Uses carrier proteins Molecules combine with carrier proteins. These molecules speed up the passage over the membrane. Glucose

14. Osmosis

15. Tonicity is a relative termFLASH CARD ALERT!!! Hypotonic Solution - One solution has a lower concentration of solute than another.Hypertonic Solution - one solution has a higher concentration of solute than another.Isotonic Solution - both solutions have same concentrations of solute.

16. Plant and Animal Cells put into various solutions

17. Carrier Proteins CARRIER PROTEINS – bind to a specific type of diffusing molecule. They have a highly specific hydrophilic region to which the solute molecule binds. This binding cause the protein to undergo a change in shape that moves the solute across the bilayer and release it on the other side

18. Active Transport Active transport is the transport of molecules by carrier proteins AGAINST a concentration gradient.REQUIRES ENERGY IN THE FORM OF ATP

19. Types of Transport

20. http://www.youtube.com/watch?v=sdiJtDRJQEc&safety_mode=true&persist_safety_mode=1&safe=active