Cellular Transport

Cellular Transport involves the Cell Membrane! PASSIVE TRANSPORT –E–E–E–Energy not required DIFFUSION OSMOSIS –H–H–H–Hypertonic –H–H–H–Hypotonic –I–I–I–Isotonic –O–O–O–Osmoregulation FACILITATED DIFFUSION ACTIVE TRANSPORT –E–E–E–Energy REQUIRED! ENDOCYTOSIS –C–C–C–Carrier Mediated –P–P–P–Phagocytosis –P–P–P–Pinocytosis EXOCYTOSIS

–Passive Transport –Passive Transport = Energy not required. Diffusion 1. Diffusion = molecules move from an area of high concentration to an area of low concentration.

Diffusion Diffusion is the driving force behind the movement of many substances across the cell membrane.

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Diffusion IF Diffusion will occur IF : concentration gradient A.There is a concentration gradient across the cell membrane. permeable B.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.

2 nd Type of Passive Transport: Osmosiswater cell membrane. Osmosis: The diffusion of water across the cell membrane. How does water know whether to move into or out of a cell?

Hypertonic solution: Hypertonic solution: The solution with the higher concentration of solutes. Hypotonic solution: Hypotonic solution: The solution with a lower solute concentration.

Isotonic solution: Solutions of equal concentration of solutes.

Egg Cell in hypertonic vs. hypotonic solution dscreen&NR=1&v=SSS3EtKAzYchttp:// dscreen&NR=1&v=SSS3EtKAzYc

3 rd Type of Passive Transport: Facilitated Diffusion: 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.

Survival Water Cell Survival Depends on the Proper Balancing of Water Uptake and Loss Animalshypo- hypertonic adaptations osmoregulationAnimals that live in hypo- or hypertonic environments must have adaptations for osmoregulation.

ParameciumThe protist Paramecium has a contractile vacuole that pumps water out as it enter.

Paramecium – vacuole pumping out water CKYc&feature=related CKYc&feature=related

The cells of plants, prokaryotes, and fungi have cells walls, which keeps the cell from bursting.The cells of plants, prokaryotes, and fungi have cells walls, which keeps the cell from bursting.

turgidA 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.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. Sodium-Potassium Pump exchanges Na+ for K+ across the plasma membrane of an animal cell.

hill.com/sites/ /student_view0/chapter2/animation__how_the_sodiu m_potassium_pump_works.html

membrane potential.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 1.E ndocytosis = The cell membrane surrounds and engulfs large particles. 1.C arrier Mediated Endocytosis = involves carrier proteins on membrane 2.P hagocytosis = Cells bring in large, solid particles (“cellular eating”) 3.P inocytosis = Cells take up liquid. (“cellular drinking”)

Carrier Mediated Endocytosis

Phagocytosis (Endocytosis)

Pinocytosis (Type of Endocytosis)

2.Exocytosis 2.Exocytosis = Cells remove large particles.

Exocytosis

The End