Lecture 11 Flashcards
What is permeable through the plasma membrane?
gases and small uncharged molecules
Channels
class 1 membrane transport proteins, facilitated transport = no energy, with gradient
ATP-powered pumps
class 2, active transport, hydrolysis of ATP, against gradient
Transporters
class 3, “secondary” active transport: uniporter, symporter, antiporter, does not use ATP – CO-TRANSPORT
Uniporter
with gradient, facilitated transport, import large molecules
Symporter
transporting 2 different molecules SAME direction | ex: Na+/lysine symporter
Antiporter
transporting 2 different molecules DIFFERENT direction | ex: anion antiporter to transport CO2 by RBCs
What powers the antiporter and symporter
moving molecules with its concentration gradient generate energy the membrane transport protein uses
P-Class ATP pump
actual pump gets phosphorylated
What membrane transport proteins are found on lysosomal membranes?
V and F-class ATP pumps
V- & F-class ATP pumps
move H+ ions
ABC superfamily ATP pump consists of
2 ATP binding domains and 2 transmembrane domains
Purpose of transcellular transport
to keep environments balanced i.e.: blood @ pH7, parietal cells @ pH7, stomach lumen @ pH1