membrane transport Flashcards
what is required for the ABC-TRANSPORTER( atp binding cassette transporter) to pump lipids outside the cell?
ATP
what type of transport does ABC-transporter have?
passive transport with the excepion of CFTR
What type of transporter is CFTR( cystic fibrosis transmembrane conductance regulator)?
ABC trnsporter
What type of channel does cystic fibrosis transmembrane conductance regulator trnasporter?
ligated gated cl- channel
How is the chloride ion channel opened?
CFTR is opened by protein kinase A , which phosphorylates CFTR. ATP is hydrolyzed and it donates its inorganic phosphate group to protein kinase to pickup and use.
what happens after protein kinase A phosphorylates and open the CFTR transporter?
cAMP
how many alpha helix groups make up the gated channel?
2 groups of 6 alpha helixes
Where is CFTR found?
in the epithelial cells
when CFTR is opened what comes through the gated channel?
Na+, Cl-,H20. chlorine first comes into the channel and Na+and H2O follow
what happens if there is a defect in the CFTR transporter?
no chlorine, means no Na+ or water following, which cause a thick mucus in the lung and pancreatic duct
what are the symptoms of Cystic Fibrosis?
salty skin, meconium( forst stool a baby passes), clubbing of the fingers, poor weigh gain, no vas deferens-infertility
what are the genetic defects of cystic fibrosis?
there is a 3 base pair deletion, loss of phenylalanine at codon 508
what is the sweat test?
it is a test that test for increase od NaCl(salt) on the skin( sweat is mostly NA+ due to Cl- reabsorption by CFTR in normal humans
how is CFTR opposite in sweat glands ?
CFTR leads to release of chloride ion into the extracellular space, but in the secretory duct the sweat glands, where chloride ions flow from the salty extracellular sweat into the duct cells
is membrane transport passive or active transport?
both
