Abstract
Phosphate can distribute in the cell wall space, but is not bound to an appreciable extent at the cell surface in non-metabolizing yeast. During metabolism of sugars, phosphate is actively transported into the yeast cell by a mechanism specifically involving glycolysis reactions. The movement of phosphate is in the inward direction only (no appreciable efflux), and it can proceed against a concentration gradient of 100 to 1. It is dependent on external phosphate concentrations in an asymptotic relationship, but is independent of the cellular orthophosphate concentration. The pH optimum for the phosphate uptake of 6.5 is shifted to the acid side by potassium. At certain values of pH a stimulation of 700 per cent by potassium can be observed. The nature of the effects of K+ and H+ are discussed.
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Selected References
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- CONWAY E. J., DOWNEY M. An outer metabolic region of the yeast cell. Biochem J. 1950 Sep;47(3):347–355. doi: 10.1042/bj0470347. [DOI] [PMC free article] [PubMed] [Google Scholar]
- MEYERHOF O., GREEN H. Transphosphorylation by alkaline phosphatase in the absence of nucleotides. Science. 1949 Nov 11;110(2863):503–503. doi: 10.1126/science.110.2863.503. [DOI] [PubMed] [Google Scholar]
- PRANKERD T. A., ALTMAN K. I. A study of the metabolism of phosphorus in mammalian red cells. Biochem J. 1954 Dec;58(4):622–633. doi: 10.1042/bj0580622. [DOI] [PMC free article] [PubMed] [Google Scholar]
- SCHMIDT G., HECHT L., THANNHAUSER S. J. The effect of potassium ions on the absorption of orthophosphate and the formation of metaphosphate by bakers' yeast. J Biol Chem. 1949 Apr;178(2):733–742. [PubMed] [Google Scholar]
- WIAME J. M. The occurrence and physiological behavior of two metaphosphate fractions in yeast. J Biol Chem. 1949 Apr;178(2):919–929. [PubMed] [Google Scholar]