Passive Transport Definition: Type 1 Type 3 Type 2 DIFFUSION OSMOSIS The process of substances passing through the cell membrane WITHOUT ANY INPUT OF ENERGY BY THE CELL. Passive Transport Type 1 Type 3 Type 2 DIFFUSION OSMOSIS FACILITATED DIFFUSION Definition: Solute molecules move from an area of high concentra-tion to an area of low conc. Powered by the random motion of molecules. Key Term: Equilibrium Definition: Cell uses carrier proteins in membrane to allow the diffusion of molecules that can’t pass through membrane alone. Hypertonic: Solute conc. Bigr outside. H2O out Definition: Diffusion of water from an area of high H2O conc. (low solute conc.) to low (high solute conc.) Required for Ions (charged molecules) Isotonic: Solute conc. = Inside & out. No net H2O change. And Hypotonic: Solute conc. Lower outside. H2O in. Hypo-Hippo Large Molecules

Active Transport Active transport processes are different from passive ones: Energy is required. Substances move UP their concentration gradients from lower conc. to higher. Equilibrium is PREVENTED.

Endocytosis “Endo-” means in. “cyto-” means cell. “osis” means process of. What does endocytosis mean? Endocytosis: the process by which cells take in large amounts of material, by folding in the cell membrane

Endocytosis Example Pinocytosis: non-specific endocytosis of small amounts of extracellular fluid. Greek: “pino-” = “drinking”

Endocytosis Example Phagocytosis: the endocytosis of solid particles such as bacteria, cell debris, or other solids Greek: “phago-” = “eating”

Phagocytes Phagocytes, such as some types of white blood cells, engulf foreign cells by phagocytosis.

For Protists, Phagocytosis = Eating

Exocytosis Exocytosis is the same process as endocytosis, except in reverse. The stuff leaving may be: Proteins released into the ECF New lipids for expanding the membrane Membrane proteins Chemicals for communication, etc. (e.g. dopamine)

Exocytosis

Endo and Exocytosis – quick review