Question

1. In the second experiment, you perform everything the same way you did in the first, but this time you replace the air in each flask with nitrogen gas (N₂) which is essentially inert before you begin. Graph the data, and be sure to display the equations of the trendlines for each condition. Insert your graph below the data table and answer the following questions.

Time (minutes)	no sugar	glucose	sucrose	maltose	lactose	galactose
0	0	0	0	0	0	0
5	0	0.3	0.2	0.25	0.1	0.1
10	0	0.5	0.4	0.45	0.2	0.15
15	0	0.7	0.6	0.65	0.3	0.2
20	0	0.9	0.8	0.85	0.3	0.3
25	0	1.1	1	1.05	0.3	0.3
30	0	1.3	1.2	1.25	0.3	0.3
35	0	1.5	1.4	1.45	0.3	0.3
40	0	1.7	1.6	1.65	0.3	0.3
45	0	1.9	1.8	1.85	0.3	0.3
50	0	2.1	2	2.05	0.3	0.3
55	0	2.3	2.2	2.25	0.3	0.3
60	0	2.5	2.4	2.45	0.3	0.3

a) How does the rate of glucose consumption compare with the first experiment you did?

b) Do you think yeast is performing cellular respiration? Why or why not.

Answer 1

a) In the first experiment, the consumption of glucose was much more and the rest of the sugars were not consumed at all. The inert Nitrogen gas allows to provides an anaerobic condition that allows the consumption of all possible sugars available to the yeast to survive in the condition. Thus all the sugars are consumed in this case but the rate of glucose consumption is much less as compared to the previous experiment.

b) Here, in this experiment, the yeast does not perform cellular respiration to much extent at first but later at a better rate. The inert condition creates a non reactive state inside the jar thereby decreasing the rate of cellular respiration because that requires a lot of glucose. The other sugars are consumed more than the glucose here signifying that the yeast was first unable to undergo cellular respiration because glucose wasn't easily consumed but later the availability of other sugars allowed a bit of cellular respiration.