transport across membranes

Question 1

what i can remember

Answer 1

osmosis-movement of water from high to low conc
diffusion- substances from high to low conc, for lipid soluble, small or uncharged mols
across semi-permeable membrane can also say from high water potential to low
facilitated diffusion-larger or CHARGED molecules through channel proteins OR CARRIER ,
THROUGH TRANSMEMBRANE PROTEIN
still down conc gradient
active transport-larger or insoluble mols against conc gradient through carrier proteins, requires ATP

Question 2

how do small dipolar molecules like water cross membranes

Answer 2

by simple diffusion but very slowly

Question 3

how does ATP work in active transport

Answer 3

hydrolyses to form ADP and pi
pi reacts with water
realeases energy changing shape of carrier protein to allow substance through

Question 4

which part of exo and endo cytosis requires energy

Answer 4

vesicle fusing with membrane

Question 5

explain how osmosis will be affected if large quantities of amylopectin are hydrolysed

glucose can be stored as amylose and amylopectin

Answer 5

amylopectin hydrolysed to produce glucose
glucose is soluble
so water potential will be higher outside cell/cell will be hypertonic
net movement of water will be inside cell

Question 6

hypertonic definition

Answer 6

having a higher amount of solutes in the water, lowering water potential

Question 7

describe glycogens structure

Answer 7

-contains 1,4 and 1,6 glycosidic bonds
-compact
-highly branched, more than amylopectin
-storage mol in fungi and animals not plants