Following are several historical observations that led to the elucidation of the glycolytic pathway. In each case, suggest a metabolic basis for the observed effect, and explain the significance of the observation for the elucidation of the pathway. a. Alcoholic fermentation in yeast extracts requires a heat-labile fraction originally called zymase and a heat-stable fraction (cozymase) that is necessary for the activity of zymase.
b. Alcoholic fermentation does not take place in the absence of inorganic phosphate.
c. In the presence of iodoacetate, a known inhibitor of glycolysis, fermenting yeast extracts accumulate a doubly phosphorylated hexose.
d. In the presence of fluoride ion, another known glycolytic inhibitor, fermenting yeast extracts accumulate two phosphorylated three-carbon acids.