Why did the substitution of arsenate for phosphate prevent the accumulation of fructose 1,6-bisphosphate yet allow fermentation to ethanol and CO to go to completion? Arsenate replaces in the glyceraldehyde 3-phosphate dehydrogenase reaction to yield an acyl arsenate, which spontaneously hydrolyzes. This prevents the formation of while allowing 3-phosphoglycerate to continue through the pathway and preventing the accumulation of fructose 1,6-bisphosphate