Presentation on theme: "Maintaining Homeostasis"— Presentation transcript:
1 Maintaining Homeostasis Passive and Active Transport
2 Lesson ObjectivesUnderstand how equilibrium is established as a result of diffusion.Distinguish between diffusion and osmosis.
3 Cellular MembraneMembrane: function is to control what enters and exits the cellSelectively permeable
4 Homeostasis All living cells exists in a liquid environment Internal conditions need to remain constantHomeostasisEquilibrium=everything is balancedMaintain homeostasis by regulating movement of molecules across the membranePassive Transport (no energy required)Active Transport (energy required)
5 Passive Transport: Diffusion Movement of materials across the cell membrane without using energyDiffusion:Movement of material/molecules from an area of high concentration to an area of low concentrationConcentration Gradient
6 Passive Transport: Osmosis When water diffuses across the cell membranehill.com/sites/ /student_view0/chapter2/animation__how_osmosis_works.htm l
7 Effects of Osmosis on Cells Hypotonic:Hypertonic:Isotonic:Lower solute concentration outside of the cellHigher solute concentration outside of the cellConcentration is the same inside and outWater moves into the cellWater moves out of the cellWater moves in and outCell swellsCell Shrinks
13 Osmosis In NatureCytolysis: in a hypotonic solution red blood cells will continue to swell until they burstPenicillin killing bacteriaContractile Vacuole: organelle in protist cells that pumps excess water outTurgor Pressure: water pressure placed on the cell wall to give plant cell its shapePlants wilting if solution is hypertonicDon’t drink salt waterDiarrheaSomething in stools that is drawing out the water
14 Facilitated Diffusion Movement of particles from higher concentration to lower concentrationLarge molecules may require “help”, they use carrier proteinsNervous 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