The effect of bivalent cations on phosphate uptake by Saccharomyces cerevisiae was investigated. Phosphate uptake via the Na+-dependent transport system at pH 7.2 is stimulated by bivalent cations. The apparent affinity of phosphate for the transport mechanism is increased, but the apparent affinity for Na+ is decreased. Uptake of phosphate via the Na+-independent transport system is accompanied by a net proton influx of 2H+ and an efflux of 1 K+ for each phosphate ion taken up. At pH 4.5 phosphate uptake via the Na+-independent system is stimulated by bivalent cations, whereas at pH 7.2 uptake is inhibited. The effect of bivalent cations on phosphate uptake can be ascribed to a decrease in the surface potential.
Skip Nav Destination
Research Article| March 15 1979
Interaction of cations with phosphate uptake by Saccharomyces cerevisiae. Effects of surface potential
Biochem J (1979) 178 (3): 521–527.
- Views Icon Views
- Share Icon Share
G M Roomans, G W F H Borst-Pauwels; Interaction of cations with phosphate uptake by Saccharomyces cerevisiae. Effects of surface potential. Biochem J 15 March 1979; 178 (3): 521–527. doi: https://doi.org/10.1042/bj1780521
Download citation file: