1. Active Transport Biology Unit V - Regulation

2. Active Transport Molecules move UP the concentration gradient Molecules move from an area of lower concentration to an area of higher concentration Requires energy (ATP)

3. Active Transport Thousands of proteins are embedded in the cell's lipid bilayer. These proteins do much of the work in active transport. They are positioned to cross the membrane so one part is on the inside of the cell and one part is on the outside.

4. Example of Active Transport

5. Active Transport Occurs a lot in neurons. The membrane proteins are constantly pumping ions in and out to get the membrane of the neuron ready to transmit electrical impulses.

6. Passive & Active Transport

7. Comparison of diffusion, osmosis and active transport. DIFFUSIONOSMOSISACTIVE TRANSPORT Energy requirements ATP not required ATP required Distance of travel Solutes and gases- long distances Solvent (water)- short distancesShort distances Speed of process Rapid in gases, slow in solution Slow processRapid process Definition Transport of gases or dissolved substances (solutes) in solution from a region of high concentration to a region of lower concentration of the transported substance. Transport of a solvent (water) through a semipermeable membrane from a solution of low solute concentration to a solution of higher solute concentration. Transport of a substance from lower to higher concentration of that substance, using energy from the cell, through a living cell membrane. Examples Uptake of oxygen by a cell performing aerobic respiration. Oxygen continues to diffuse into the cell as O 2 is removed by respiration. The movement of water into cells of a marine (salt water adapted) animal placed in fresh water. May eventually cause cells to swell and burst. Transport of glucose against its concentration gradient from the gut lumen into the cells lining the intestine.