The effect of calcium on the respiratory responses of corn mitochondria.
Tightly coupled respiring corn mitochondria (Zea mays L.) respond to calcium addition with a transitory respiratory increase, proton extrusion, and Ca2+ binding. The extent of response is dependent upon the level of endogenous phosphate, and a large sustained respiratory increase can be obtained with addition of phosphate. However, calcium does not act as a permeant cation in that it will not penetrate with acetate. It appears that the transitory respiratory increase must be linked to the uptake of a calcium phosphate complex, but there is no evidence that transport of the complex serves to produce an electrophoretic calcium uniport. It is believed that calcium phosphate transport in corn is a constitutive property, and not produced by membrane damage.
D000085:Acetates / Q000378:metabolism; D001665:Binding Sites; D001692:Biological Transport; D002118:Calcium / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D008928:Mitochondria / Q000378:metabolism*; D008933:Mitochondrial Swelling; D010101:Oxygen Consumption; D010710:Phosphates / Q000378:metabolism*; D003313:Zea mays / Q000378:metabolism* / Q000648:ultrastructure
D000085:Acetates; D010710:Phosphates; D002118:Calcium