moving materials into and out of the cell transport through the cell membrane extracellular fluid ~...
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Cell TransportMoving Materials Into and Out of the Cell
Transport through the cell membraneExtracellular fluid ~ The fluid that surrounds
cells. (Interstitial fluid)Intracellular fluid ~ The fluid inside of a cell.
(Cytosol)
Plasma MembraneRegulates what enters and leaves the cell and
also provides protection and support.
Phospholipid bilayer
Plasma MembraneSemi-permeable or selectively permeable
Proteins – channels and pumps that help to move material across the cell membrane.
Carbohydrates – act like chemical identification cards
SolutionSolvent – substance that contains
substances; responsible for doing the dissolving
Solute – substance dissolved in the solvent
Ex: salt water Salt = solute water = solvent
ConcentrationCytoplasm contains a solution of may
different substances in water
Amount of substances vs amount of water
Concentration gradient – drives diffusion and osmosis
Hypotonic, Hypertonic, IsotonicHypotonic – lower concentration of solutes
Hypertonic – higher concentration of solutes
Isotonic – concentration is the same
Ext
race
llula
r F
luid Intracellular F
luid
Ext
race
llula
r F
luid Intracellular F
luid
Isotonic solution ~ The concentration of dissolved salts in the intracelluar fluid is the same as it is in the extracellular fluid.
Note that normal red blood cells look a bit like Cheerios. They are round and flat with a dent in
the middle.
Hypertonic solution ~ The concentration of dissolved materials is greater in the
extracellular fluid than it is in the intracellular fluid.
Plasmolysis ~ Cell shriveling due to a decrease in internal pressure.
Hypotonic solution ~ The concentration of dissolved materials in the intracellular
fluids is greater than that in the extracellular fluid.
Cytolysis ~ Cell bursting due to internal pressure.
Dynamic equilibriumThe point at which concentrations of a
molecule or compound is equal both inside and outside.
Passive TransportPassive transport is the movement of
materials through the cell membrane that does not require the use of energy.Diffusion ~ The movement of particles from an
area of high concentration to low concentrationOsmosis ~ The diffusion of water through a
semi-permeable membrane. In the case of cells, this will be the cell membrane.
Passive DiffusionMovement of substances is through the cell
membrane from a high concentration to low concentration
Osmosis is a type of passive diffusion where water molecules across the cell membrane
Facilitated DiffusionSubstances cross the cell membrane through
protein channels (specifically designed for that substance)
No energy is used
http://www.youtube.com/watch?v=AYNwynwaALo
Active TransportMovement of substances into and out of the
cell using energy
Protein pumps are necessary; changes in protein shapes is vital for this to occur
Active TransportRequires the use of cell energy (ATP)
Endocytosis: process of taking material into the cell by folding of the cell membrane.Phagocytosis: “cell eating”Pinocytosis: cell takes in liquid from outside
the cell
Active TransportExocytosis: release of materials from the cell
Membrane of the vacuole surrounding the material fuses with the cell membrane, forcing the contents out of the cell
Videos!!Plasma Membrane:
http://www.youtube.com/watch?v=owEgqrq51zY&feature=related
Facilitated diffusion: http://www.youtube.com/watch?v=s0p1
ztrbXPY&NR=1Active Transport:
http://www.youtube.com/watch?v=STzOiRqzzL4