The hexosephosphate formed by yeast-juice from hexose and phosphate

Abstract

It has been shown by Harden and Young that—(1) the rate of fermentation of glucose by yeast-juice is greatly increased by the addition of a soluble phosphate; (2) this rate soon diminishes until a constant rate is attained, which is only slightly greater than that of the original yeast-juice and glucose; (3) during this period of increased fermentative activity, the phosphate undergoes some alteration, and at the end of the period is no longer present in a form precipitable by magnesium citrate mixture. The authors suggested in the first paper that a combination of the phosphate with the sugar, to form a phosphoric acid ester, had taken place, and more recently embodied this suggestion in the form of an equation— 2C₆H₁₂O₆ + 2R´₂HPO₄ = 2CO₂ + 2C₂H₆O + C₆H₁₀O₄(PO₄R´₂)₂ + 2H₂O. It has also been shown that the same phenomena occur when fructose or mannose is used in place of glucose.