CHS Biology Ch 5

proteins

carrier molecules in active transport

equilibrium

concentration of molecules is the same throughout a space

concentration gradient

difference in the number per unit volume of ions or molecules of a substance between adjoining regions

simple diffusion

the movement of any kind of molecule from areas of higher concentration to ones of lower concentration

endocytosis

the process by which a cell surrounds and engulfs substances

facilitated diffusion

the process whereby a protein assists in simple diffusion

tonicity

the relative solute concentrations of two fluids

active transport

this process explains the movement of molecules against a concentration gradient

osmosis

this process specifically moves water molecules across a differentially permeable membrane

isotonic

two solutions that have equal numbers of solutes

traits of endocytosis

two types; type of active transport; require energy; cells ingest (eat)

phagocytosis

a type of endocytosis in which a cell engulfs large particles or whole cells

wilting

affect of cell in hypertonic solution

swelling

affect of cell in hypotonic solution

sodium-potassium pump

an example of facilitated diffusion

What affects the rate of diffusion?

steepness of concentration gradient, size of solute, temperature

hydrostatic pressure

force that any volume of fluid exerts against a wall, a membrane, or some other structure enclosing it

hypotonic

has fewer solutes than the other compartment

hypertonic

has more solutes than other compartment

turgor pressure

hydrostatic pressure that is specific to plants

plasmolysis

in a hypertonic environment, water leaves the cells through osmosis, making the cells shrink away from the cell walls

cytolysis

in a hypotonic environment, water diffuses into the cells, causing them to swell and burst

phagocytosis

ingest bacteria and viruses; transports large particles or whole cells

More heat energy

makes molecules move faster = faster diffusion rates

bulk flow

mass movement of one or more substances in response to pressure, gravity, or another external force

selective permeable

molecular structure allows some substances to cross it, but not others

glucose

needs a transport protein to cross cell membrane