channel proteins permits a continuous, unimpeded flow of molecules.
transporters must first collect, bind and shift conformation to release on the other side of the membrane and then reset to their original shape and the cycle will happen all over again
normal vs mutated CFTR
CFTR is responsible for the movement of Cl- out a cell (those that control mucus and such) and outside the cell there is a high level of Na which diffuses into the cell (high to low concentration) pushing the Cl- out. H2O comes in to balance the charge which keeps mucus thin and fluid and able to process through and keep airways clear.
why is one nucleotide change in CFTR so lethal?
a point mutation in DNA can change the sequence and overall folding of the protein
the conformational change makes ATP binding less efficient thus disrupting channel function and in this case makes Cl- passage more difficult