Question

You are monitoring the metabolism of two different cultures of the same species of yeast, which you have labeled Culture A and Culture B. One of your observations is that Culture A is using up about 10 times the amount of glucose per unit of time as Culture B. Which one of the following conclusions could you reasonably draw regarding these cultures?

A. Culture A would be accumulating lactic acid.
B. Culture A is being grown aerobically; Culture B is being grown anaerobically.
C. Only Culture A is recycling its NADH back to NAD+.
D. Culture A and Culture B are synthesizing the same amount of ATP per unit of glucose in glycolysis.
E. None of the above conclusions could be drawn from the information given.

Answer 1

Answer: D

Explanation: The experiment was set up using the very same species of yeast labeled differently. What this means is that they are of the same type or kind and thus would exhibit similar features from feeding to the metabolism of the food they take and subsequent production of by-products of the fermentation process. In this regard, therefore, the reasonable conclusion that can be drawn regarding these cultures is that both cultures A and B are synthesizing the same amount of ATP per unit of glucose in glycolysis (the cellular degradation of the simple sugar glucose to yield pyruvic acid, and ATP as an energy source).