membrane proteins Flashcards
what are the types of membrane proteins?
channels transporters integrins/adhesins/connexins/claudins receptors enzymes
how do channel proteins work?
use facilitated diffusion to move molecules down a concentration gradient
use charge to be selective
how does a passive membrane transporter work?
binding of the ligand causes a shape change
solute binding can move into the cell down an electrochemical gradient
how does an active membrane transporter work?
solute binds to the transporter
causes ATP to bind and be hydrolysed to release energy
changes the shape
solute can move in against the electrochemical gradient
what is primary active transport?
ATP hydrolysis provides the energy to move molecules against the electrochemical gradient
what is secondary active transport?
energy is stored when there is movement of a solute down an electrochemical gradient - used to move another solute down
e.g. sodium glucose transporter in intestinal epithelium
what is an antiporter?
co-transports two molecules in opposite directions
what is a symporter?
co-transports two molecules in synergy
explain how receptor mediated endocytosis works?
particles bind to the receptor
it bends in on itself and invaginates to form a vesicle
vesicles can be transported inside the cell
what is cholestasis?
when bile cannot flow from the liver to the duodenum
what causes cystic fibrosis?
mutations in the CFTR means that Cl- is transported outside of the cell which thins mucus secretions bc Na+ and water follow
what is the inheritance pattern of cystic fibrosis?
autosomal recessive
