Question

Yeast cells need the same amount of ATP, regardless of its source. Assume that they need 36 moles of ATP. Based on the equations of cell respiration and fermentation, how many moles of glucose will be used if the cells carry out (show your calculations)

Answer 1

One mole of glucose yields 36 moles of ATP during aerobic respiration, so yeast would need one mole of glucose. In contrast, fermentation only produces 2 moles of ATP per mole of glucose, therefore 18 moles of glucose would be necessary for 36 moles of ATP.

Step-by-step explanation:

When considering the number of moles of glucose required for yeast cells to produce 36 moles of ATP, we need to differentiate between aerobic respiration and fermentation. In aerobic respiration, one mole of glucose theoretically yields 36 moles of ATP. Therefore, to meet the requirement of 36 moles of ATP, only one mole of glucose would be needed.

However, during fermentation, the yeast cells are limited to glycolysis, which yields only 2 moles of ATP per mole of glucose. Hence, to produce 36 moles of ATP, the yeast would require 18 moles of glucose (36 moles of ATP / 2 moles of ATP per mole of glucose = 18 moles of glucose).