Question

Yeast poison themselves to death when the concentration of alcohol reaches about

Answer 1

Answer:

about approximately 14%

Explanation:

this is because the optimum conditions, required for the yeast to respire efficiently, are altered. the optimum PH required for the fermentation of glucose by the yeast is around 5.5. However, ethanol being a weak acid, with a PH of around 4, it denatures the respiratory enzymes of the yeast which are used in fermentation, zymase and invertase. without the respiratory enzymes, the yeast isn't able to respire, and eventually dies. Thus, high concentrations of ethanol are toxic to the yeast.