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Cellular Transport. PASSIVE TRANSPORT Energy not required DIFFUSION OSMOSIS Hypertonic Hypotonic Isotonic Osmoregulation FACILITATED DIFFUSION. ACTIVE TRANSPORT Energy REQUIRED ! ENDOCYTOSIS Carrier Mediated Phagocytosis Pinocytosis EXOCYTOSIS.
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PASSIVE TRANSPORT Energy not required DIFFUSION OSMOSIS Hypertonic Hypotonic Isotonic Osmoregulation FACILITATED DIFFUSION ACTIVE TRANSPORT Energy REQUIRED! ENDOCYTOSIS Carrier Mediated Phagocytosis Pinocytosis EXOCYTOSIS Cellular Transport involves the Cell Membrane!
Passive Transport = Energy not required. 1. Diffusion= molecules move from an area of high concentration to an area of low concentration.
Diffusion is the driving force behind the movement of many substances across the cell membrane.
More on diffusion • http://www.youtube.com/watch?v=STLAJH7_zkY
Diffusion will occur IF: • There is a concentration gradient across the cell membrane. • Solution or membrane is permeable.
NOTE! The cell membrane is semi-permeable, which means only small molecules or fat soluble molecules can pass across the membrane without help. • Permeable: It can pass. • Impermeable: Cannot pass.
2nd Type of Passive Transport: Osmosis: The diffusion of wateracross the cell membrane. How does water know whether to move into or out of a cell?
Hypertonic solution: The solution with the higher concentration of solutes. Hypotonic solution: The solution with a lower solute concentration.
Isotonic solution: Solutions of equal concentration of solutes.
Egg Cell in hypertonic vs. hypotonic solution • http://www.youtube.com/watch?feature=endscreen&NR=1&v=SSS3EtKAzYc
3rd Type of Passive Transport: 3. Facilitated Diffusion: Molecules are transported across the cell membrane by a carrier protein. Ex. Glucose is carried into a red blood cell by a carrier protein.
Cell SurvivalDepends on the Proper Balancing of Water Uptake and Loss • Animals that live in hypo- or hypertonic environments must have adaptations for osmoregulation.
The protistParameciumhas a contractile vacuole that pumps water out as it enter.
Paramecium – vacuole pumping out water • http://www.youtube.com/watch?v=pahUt0RCKYc&feature=related
The cells of plants, prokaryotes, and fungi have cells walls, which keeps the cell from bursting.
A cell is turgid (firm) when the back pressure of the cell wall on the cell opposed any further water uptake.
A cell is flaccid(limp) when its surroundings are isotonic and there is no net tendency for water to enter the cell.
Active Transport • Essential in the ability of a cell to maintain internal concentrations of small molecules. It is the pumping of molecules against their gradients. ATP supplies the energy.
Sodium-Potassium Pump exchanges Na+ for K+ across the plasma membrane of an animal cell.
https://highered.mcgraw-hill.com/sites/0072495855/student_view0/chapter2/animation__how_the_sodium_potassium_pump_works.htmlhttps://highered.mcgraw-hill.com/sites/0072495855/student_view0/chapter2/animation__how_the_sodium_potassium_pump_works.html
All cells have electrical potential energy (voltage) across their plasma membranes. This is called a membrane potential. • The inside of a cell is ---, and the outside is +, which causes the membrane to favor the passive transport of cations into the cell.
ACTIVE TRANSPORT • Endocytosis= The cell membrane surrounds and engulfs large particles. • Carrier Mediated Endocytosis= involves carrier proteins on membrane • Phagocytosis= Cells bring in large, solid particles (“cellular eating”) • Pinocytosis= Cells take up liquid. (“cellular drinking”)
