1.What does the presence of lactic acid in a sample indicate about what process is occurring in each cell fraction?
2.Explain why lactic acid was produced by the cytoplasm fraction incubated with glucose, but not the mitochondrial fraction.
3.Why was no carbon dioxide produced by either fraction incubated with glucose?
4.Why did the cytoplasm fraction produce lactic acid in the presence of both glucose and pyruvate?
5.Why did the mitochondria produce carbon dioxide in the presence of pyruvate but not in the presence of glucose?
6.If the conversion of pyruvate to lactate does not generate ATP, what is the purpose of this reaction? (Hint: look at all of the products of the reaction).
7.If the Krebs Cycle does not generate that much ATP, what is it doing? What is its main product that drives respiration forward?
8.Where is ATP made in the mitochondrion? Be careful with this one. After you state where ATP is made, tell us how protons and chemiosmosis are involved.
9.When people are first learning about cellular respiration, they often say that the oxygen we inhale is turned into the carbon dioxide we exhale. Is this true? Explain why or why not.
10.Describe the differences between starch, cellulose and glycogen. What is the purpose of each of them and where are they each found?
