1. CELL MEMBRANES AND TRANSPORT

2. HOW DO CELLS GET NUTRIENTS AND WATER? HOW DO CELLS RELEASE WASTES?
Moving substances across the selectively permeable membrane
Selectively permeable = allowing some substances to pass through

3. CELL MEBRANE Gatekeeper of the cell
Fence to keep substances not needed out of the cell
A fence to move in important substances into the cell
CELL MEBRANE

4. FLUID MOSAIC MODEL OF CELL MEMBRANE
Composed of proteins, carbohydrates, lipids; proteins move in the membrane; not rigid; flexible

5. TYPES OF MOVEMENT OF SUBSTANCES ACROSS THE MEMBRANE
A. PASSIVE TRANSPORT
B. ACTIVE TRANSPORT

6. PASSIVE TRANSPORT a. Diffusion; b. Osmosis, and
= the movement of molecules across the cell membrane and does not require energy.
= dependent on the permeability of the cell membrane.
3 main kinds of passive transport –
a. Diffusion; b. Osmosis, and
c. Facilitated Diffusion.

7. Facilitated diffusion
hill.com/sites/ /student_view0/chapter2/anima tion__how_facilitated_diffusion_works.html
. Osmosis
hill.com/sites/ /student_view0/chapter2/anima tion__how_osmosis_works.html

8. OSMOSIS
Net movement of water molecules from an area of high free water concentration
( hypotonic) to an area of less free water concentration ( hypertonic) across a membrane until the concentration of free water is equal on both sides ( isotonic).
=results in increase of water level

9. OSMOSIS http://www.stjohn.ac.th/Department/school/bio_pix/osmosis.gif

11. ACTIVE TRANSPORT
Use of energy (ATP) to move substances across the membrane
From lower concentration area to high concentration (= against concentration gradient) ml
hill.com/sites/ /student_view0/ch apter2/animation/

12. ACTIVE TRANSPORT
Sodium – potassium pump
Endocytosis
Exocytosis
Phagocytosis

13. CELL MEMBRANE http://www.johnkyrk.com/cellmembrane. html
02_int_membraneweb/
enceWork/CellsOrganization.htm
CELL MEMBRANE

14. http://www.williamsclass.com/SeventhSci enceWork/CellsOrganization.htm
More links