Atp Pumps and Ion Exchangers Flashcards
What is pumped in an out in a sodium potassium pump
3 na+ out
2 k+ in
What is pumped in and out in a sodium calcium exchanger
3 na+ out
1 ca+ in
What happens to the excess ca+ in the cells
Taken up by the sarcoplasmic reticulum
How do cardiac glycosides (digoxin) work
No working ATPase no NA+ would be pumped out and would accumulate
Would activate the calcium sodium transporter
Would then allow ca+ to enter and accumulate
Would have some move to the SR
Would allow the more forceful contraction
How is the intracellular PH controlled
NHE : Na+ in and he out (acid extrusion)
NCBE : Na+ and HCO3 in and cl- and h+ out (acid extrusion)
NBC: NA+ and hco3 in (alkali influx)
AE : cl- (in) hco3 (out) ALKALI EXTRUSION
How is cells swelling controlled
Na+/k+ and organic ions would move out
Calcium would move inwards
How is cell shrinking controlled
Na+/k+ would move in as well as would the organic ions
H+ moves out
What is the main exchanger that would remove the ca+
NCX
WOULD NOT USE ATP BUT ELECTROCHEMICAL GRADIENTS
What does PMCA do
Removes the residual ca+ in the cell cytosol
What transports the CA+ to the er/sr
SERCA transporter
In descending order, which areas would contain the most ca+
Extracellular > SR/ER > intracellular
What is the resting concentration n intracellular calcium
0.1mM
Why is the electrical charge unevenly districbuted within the cells
-permeability
-electrical gradient
-concentration gradient
What is hyperkalactemia
Too much k+ on the outside of the cell
Em would then be postitive
Would lead to heart and cardiac issues
What is the Em of the membrane when it is ONLY Permeable to K+
Negative
