Passive and Active Transport Movement of material into and out of cells.
Post on 27-Dec-2015
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Passive transport is the movement of substances across the cell membrane without the use of energy by the cell
Diffusion is the movement of a substance from an area of high concentration to an area of lower concentration
Ion ChannelsIon channels are proteins that have a pore through which ions can cross the cell membrane.
Ions cannot diffuse across the cell membrane due to the lipid bi-layer.
Ion channels move ions from an area of high ion concentration to an area of low ion concentration (down the ion’s concentration gradient).
Facilitated DiffusionIn facilitated diffusion, a carrier protein transports a substance across the cell membrane down the concentration gradient of the substance
Active Transport
Active transport is the movement of a substance against the concentration gradient of the substance. Active transport requires cells to use energy
Sodium-Potassium Pump
In animal cells, the sodium-potassium pump uses energy supplied by ATP to transport sodium ions out of the cell and potassium ions into the cell
Endocytosis
Click for video of Endocytosis and Exocytosis
During endocytosis, substances are moved into a cell by a vesicle that pinches off from the cell membrane
Exocytosis
During exocytosis substances inside a vesicle are released from a cell as the vesicle fuses with the cell membrane
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