the characteristics of nonmitochondrial ca2+ uptake into leaky isolated cells and 45ca2+ uptake into isolated endoplasmic reticulum were very similar : calcium uptake was maximal at 0.3 and 0.2 mmol/liter free mg2+ , at 1 and 1 mmol/liter atp , at ph 6.0 and 6.5 , and free ca2+ concentration of 2 and 2 mumol/liter , respectively .
C0007634
cells
C0014239
endoplasmic reticulum