Question

The students then conducted their last experiment. In this case, they added a package of yeast and 2 grams of glucose to the water, which varied in temperature. Comment on the students results regarding cellular respiration in this case.
Responses
A As temperature increases, the rate of cellular respiration increases.As temperature increases, the rate of cellular respiration increases.
B The optimum temperature for cellular respiration of yeast is
C.The optimum temperature for cellular respiration of yeast is 42 o C.
C There is little impact on the rate of cellular respiration by change in water temperature.There is little impact on the rate of cellular respiration by change in water temperature.
D Cellular respiration of yeast is dependent of the presence of glucose and an appropriate temperature.Cellular respiration of yeast is dependent of the presence of glucose and an appropriate temperature.

Answer 1

Best answer: D.

Explanation: Yeast cellular respiration/fermentation requires a fermentable substrate (glucose) and an appropriate temperature range. Rate increases with temperature only up to an optimum (warmer speeds enzyme-catalyzed reactions), but above that optimum enzymes denature and the rate falls. Very low temperatures slow metabolism as well. Thus presence of glucose and an appropriate temperature are both required.