Biology 6.2 and 8.1

water, opposite, water, ions, water

- ___ is a polar molecule; it has a positive and negative end - because ___ charges attract, the ____ molecules will attract each other, loose ___, and other polar molecules - this causes many molecules to dissolve in ___, the universal solvent

water

- most important compound in living things - all chemical reactions occur in it - living organisms are 75 to 95% ____

results of diffusion

- particles in solution seek dynamic equilibrium - atoms never stop moving, so once this is reached the atoms continue moving to maintain it

exocytosis

active transport process by which materials are secreted or expelled from a cell

endocytosis

active transport process where a cell engulfs materials with a portion of the cell's plasma membrane and releases contents inside the cell

diffusion

depends on 1) concentration of substances 2) temperature 3) pressure

osmosis

diffusion of water across a selectively permeable membrane depending on the concentration of solutes on either side of the membrane

kinetic energy

energy of motion - all atoms are in constant motion

active transport

energy-expending process by which cells transport materials across the cell membrane

isotonic solution

in cells, solution in which the concentration of dissolved substances in the solution is the same as the concentration of the dissolved substances inside a cell

hypotonic solution

in cells, solution in which the concentration of dissolved substances is lower in the solution outside the cell than the concentration inside the cell; causes a cell to swell and possibly burst as water enters the cell

hypertonic solution

in cells, solution in which the concentration of dissolved substances outside the cell is higher than the concentration inside the cell; causes a cell to shrink as water leaves the cell

pressure

increased ___ increases diffusion

polar molecule

molecule with an unequal distribution of charge, resulting in the molecule having a positive end and a negative end

passive transport

movement of particles across cell membranes by diffusion or osmosis; the cell uses no energy to move particles across the membrane

diffusion

net, random movement of particles from an area of higher concentration to an area of lower concentration, eventually resulting in even distribution

facilitated diffusion

passive transport of materials across a plasma membrane by transport proteins embedded in the plasma membrane

dynamic equilibrium

result of diffusion where there is continuous movement of particles but no overall change in concentration

concentration gradient

the difference in concentration of solute across a medium

concentration of substances

the greater the difference in concentration of particles the more rapid diffusion will occur

temperature

the higher the ____, the more rapid diffusion will occur

brownian motion

the random movement of molecules

hydrogen bound

weak chemical bond formed by the attraction of positively charged hydrogen atoms to other negatively charged atoms