Passive and Active Transport Lesson Objectives Understand how equilibrium is established as a result of diffusion Distinguish between diffusion and osmosis Cellular Membrane Membrane function is to control what enters and exits the cell ID: 336673
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Slide1
Maintaining Homeostasis
Passive and Active TransportSlide2
Lesson Objectives
Understand how equilibrium is established as a result of diffusion.
Distinguish between diffusion and osmosis.Slide3
Cellular Membrane
Membrane: function is to control what enters and exits the cell
Selectively permeable Slide4
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)Slide5
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 GradientSlide6
Passive Transport: Osmosis
When water diffuses across the cell membrane
http://highered.mcgraw-hill.com/sites/0072495855/student_view0/chapter2/animation__how_osmosis_works.html
Slide7
Effects of Osmosis on Cells
Hypo
tonic
:
Lower solute concentration outside of the cell
Water moves into the cell
Cell swells
Hyper
tonic
:
Higher solute concentration outside of the cell
Water moves out of the cell
Cell Shrinks
Iso
tonic
:
Concentration is the same inside and out
Water moves in and outSlide8Slide9Slide10
How does water move? “Salt Sucks”Slide11
How does water move? “Salt Sucks”Slide12
v
v
How does water move? “Salt Sucks”Slide13
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
http://www.youtube.com/watch?v=pahUt0RCKYc&feature=related
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 waterSlide14
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 pumpsSlide15
Lesson Objectives
Distinguish between passive and active transport.
Explain how sodium-potassium pumps operate.
Compare and contrast endocytosis and exocytosis.Slide16
Active Transport
Passive Transport
: down concentration gradient
Active TransportSlide17
Active Transport
Passive
Active
Slide18
Active Transport
Requires energy to move molecules up their concentration gradient
Low concentration to high concentration
Sodium-Potassium Pump
Exocytosis
EndocytosisSlide19
Cell Membrane Pumps
Requires a carrier protein
3 Na-2 K
Requires energy
http://highered.mcgraw-hill.com/sites/0072495855/student_view0/chapter2/animation__how_the_sodium_potassium_pump_works.htmlSlide20
Endocytosis
Phagocytosis
Pinocytosis Slide21
Exocytosis