uptake vs transport - (May/22/2001 )

i have a very basic query regarding use of cell culture ot study membrane transport. what is the difference between uptake and transport. other than using two different to evaluate uptake or transport i have no clue as to what are the differences and why one would use one over the other?any inputs or thoughts will be appreciated.thanks much.pankaj

look up: allera and wildt J Steroid Biochem Mol Biol 1992 Aug;42(7):737-56