Active Transport vs. Passive Transport

Passive Transport Goes with the flow … with the gradient…. HIGH to LOW NO Energy needed

Concentration: amount of a particular substance in a given volume concentration gradient when one area has a higher concentration than another area does, a exists. NO!!!! It’s too crowded… get out!

High to low until equilibrium reached Equilibrium is a state in which a system remains unchanged over time. A space is filled evenly, equilibrium is reached. A High to low until equilibrium reached B Passive transport movement across a membrane without the use of energy (ATP).

Modes of Passive Transport 1)Diffusion Cacaused by: temp, pressure, concentration Only sm particles squeeze through 2) Facilitated Diffusion the diffusion of water … through channel proteins 3) Osmosis

Types of Osmotic Solutions Isotonic Hypotonic Hypertonic

Isotonic Same size Blood Cell Plant Cell 11,397x

Hypotonic Swell… burst Blood Cell Plant Cell 13,000x

Hypertonic shrivels Blood Cell Plant Cell 13,000x

Some unicellular eukaryotes have contractile vacuoles, which collect excess water inside the cell and force the water out of the cell. Animal cells have neither cell walls nor contractile vacuoles. Many animal cells can avoid swelling caused by osmosis by actively removing solutes from the cytoplasm.

Active Transport Against the gradient…. LOW to HIGH Requires Energy … ATP

Modes of Active Transport 3 sodium ions go OUT 2 Potassium ions go IN Is an impt carrier proteins in animal cells prevents Na+ from building up in the cell, thus preventing osmosis into the cell. 1)sodium-potassium pump (Na+/K+ ATPase Pump) Too big to use carrier proteins … use these sacs … Endocytosis takes stuff IN Exocytosis takes stuff OUT 2) vessicles

Sodium Potassium pump

Endocytosis/Exocytosis Exocytosis … same thing…just EXITS . .er uh… takes it to outside of cell