p type pumps Flashcards
p type pumps structure
simple
4 subunits
2 a
2 B
what does phosphorylation of the P type pump do
provides energy for conformational change
what kind of pumps are calcium pumps
p type pumps
function of calcium pums
restablishes normal cell concentration gradeint
necessary in all cells for muscle contrction, neural transmitter secretion, cell/ cell signaling
typical p type pump
calcium pump
p type calcium pump what does it use and what does it move
uses ATP to move two ca across the membrane
skeletal muscles and ca pumps
ions concentratied and stored in the sarcoplasmic reticulum
ion channles release stored ions into the cytosol to cause muscle contraction
ca pumps in the SR membrane pump ca back into ST resulting in muscle relaxation
E1 form of calcium pumps
- binding sites accessible via cytosolic side
-two high affinity binding sites for calicum
-ATP binding site
E2 form of caclium pumps
-after transfer of phosphate to pump from ATP confromational chagne and protein opens to exterior
-decrease affinity for calium and calcium released
return to E1 form via release of rphosphate and confromational change
Na/k p type pumps stpes
E1 open to cytool, high Na affinity
E2 open to exterior, high k affinity
phosphorylation changes from
E1 form of p type pumsp
-binding sites face cytosol
-3 high affinity na
-2 low affinity k
E2 form of p type pumps
ATP binds and transfer of pi to aspartate triggers conformational change to open the exterior
-na becomes low affinity and release na
-k sites beocomes high affinity, bind k
back to E1 form
-release of phosphate and conformational change
-k binding sites become low affinity again and k release in cytosol
what in the na/k p pump results in a confromational change
phosphorylation of the alpha subunit not binding of ATP
T/F p class calcium pumps result in the storage of ca ions in muscle cells
true
