Presentation is loading. Please wait.

Presentation is loading. Please wait.

Maintaining Homeostasis

Similar presentations

Presentation on theme: "Maintaining Homeostasis"— Presentation transcript:

1 Maintaining Homeostasis
Passive and Active Transport

2 Lesson Objectives Understand how equilibrium is established as a result of diffusion. Distinguish between diffusion and osmosis.

3 Cellular Membrane Membrane: function is to control what enters and exits the cell Selectively permeable

4 Homeostasis All living cells exists in a liquid environment
Internal conditions need to remain constant Homeostasis Equilibrium=everything is balanced Maintain homeostasis by regulating movement of molecules across the membrane Passive Transport (no energy required) Active Transport (energy required)

5 Passive Transport: Diffusion
Movement of materials across the cell membrane without using energy Diffusion: Movement of material/molecules from an area of high concentration to an area of low concentration Concentration Gradient

6 Passive Transport: Osmosis
When water diffuses across the cell membrane /student_view0/chapter2/animation__how_osmosis_works.htm l

7 Effects of Osmosis on Cells
Hypotonic: Hypertonic: Isotonic: Lower solute concentration outside of the cell Higher solute concentration outside of the cell Concentration is the same inside and out Water moves into the cell Water moves out of the cell Water moves in and out Cell swells Cell Shrinks



10 How does water move? “Salt Sucks”

11 How does water move? “Salt Sucks”

12 How does water move? “Salt Sucks”

13 Osmosis In Nature Cytolysis: in a hypotonic solution red blood cells will continue to swell until they burst Penicillin killing bacteria Contractile Vacuole: organelle in protist cells that pumps excess water out Turgor Pressure: water pressure placed on the cell wall to give plant cell its shape Plants wilting if solution is hypertonic Don’t drink salt water Diarrhea Something in stools that is drawing out the water

14 Facilitated Diffusion
Movement of particles from higher concentration to lower concentration Large molecules may require “help”, they use carrier proteins Nervous system uses Na and Ca pumps

15 Lesson Objectives Distinguish between passive and active transport.
Explain how sodium-potassium pumps operate. Compare and contrast endocytosis and exocytosis.

16 Active Transport Active Transport
Passive Transport: down concentration gradient

17 Active Transport Passive Active

18 Active Transport Requires energy to move molecules up their concentration gradient Low concentration to high concentration Sodium-Potassium Pump Exocytosis Endocytosis

19 Cell Membrane Pumps Requires a carrier protein 3 Na-2 K
Requires energy /student_view0/chapter2/animation__how_the_sodium_potassium_p ump_works.html

20 Endocytosis Phagocytosis Pinocytosis

21 Exocytosis

Download ppt "Maintaining Homeostasis"

Similar presentations

Ads by Google