c3

movement in and out of cells

diffusion

random movement of molecules higher conc lower conc down the conc region

factors affecting diffusion

conc grad, molec size, temp, dist, state matter

roles of diffusion in living organism

obtain requirements for cells, remove waste product, gas exchange for resp supply energy

osmosis

movement of water molecules from a region of high water potent to a region of low water potent down the water potent grad through a semi perm membrane until equilibrium is achieved

high w.p has _ conc. of solute

low

low w.p has _ conc of solute

high

why doesnt osmosis occur for a boiled potato

the cell membrane is damaged as high temp denatures memb protein and degrade lipid

effect of osmosis in hypertonic solu for animal cell

shrinks, water diffuses out of cell by osmosis, in rbc, crenation

plant cell in hypertonic solu

water diffuse out of cell, cell lose turgidity, become soft and floppy, plasmolyse

animal & plant cell in isotonic solution

water potent on both sides of membrane equal, no net movement, cell remains unchanged

animal cell in hypotonic solution

cell swells lyses water diffuse in cell by osmosis rbc haemolysis

plant cell in hypotonic solution

turgid and firm, press cytoplasm against cell wall, turgor pressure, does not swell because of cell wall

why can only small molecules enter visking tube / dialysis tube

other solute molecules are too large

formula for percentage change

final - initial / initial x 100

active transport

movement of particles lower conc to high conc across membrane against conc grad

requirements of active transport

living cell energy carrier protein cell membrane

how does an ion enter a cell

concentration of ion outside cell is lower than inside the cell ion moves in through active transport ion binds to active site of carrier protein energy bind to other binding site carrier protein energy causes carrier protein to change shape ion enters cell against conc gradient