Flashcards in ATP-dependent Pumps And Ion Exchangers (session 3) Deck (10):
What is the function of the Na+/K+ ATPase pump?
Forms Na+ and K+ gradients necessary for electrical excitability
Drives secondary active transport: control of pHi, regulation of cell volume, absorption of Na+ in epithelia
Why is high intracellular [Ca2+] toxic to cells?
Lots of phosphate in cells due to hydrolysis of ATP, calcium+phosphate=calcium phosphate and this leads to ossification
What are the primary active transport mechanisms for controlling resting [Ca2+]?
PMCA expels Ca2+ out of the cell
SERCA accumulates Ca2+ into SR/ER
What is the secondary active transport mechanism for controlling resting [Ca2+]?
What is the facilitated transport mechanism for controlling resting [Ca2+]?
Mitochondrial Ca2+ uniports
How many Na+ and Ca2+ does NCX exchange?
3 Na+ for every 1 Ca2+
Give examples of acid extruders in the control of cell pH
Na+/H+ exchanger (NHE)
Na+ dependent Cl-/HCO3- exchanger (NBC=sodium bicarbonate cotransporter)
Give an example of a base extruder
Cl-/HCO3- exchanger (AE=anion exchanger)
What is NHE inhibited by?
Amiloride (potassium sparing diuretic-stops K+ entering urine)