Question

Mitochondria function questions

1. Why do you think there was no change in the O2 concentration when the pyruvate only solution was added?

2. Why do you think there was no change in the O2 concentration when the ADP only solution was added?

3. Why do you think there WAS a change in the O2 concentration when the Pyruvate and ADP together solution was added?

4. Why do you think there was no change in the O2 concentration when the Rotenone only solution was added?

5. Why do you think there was no change in the O2 concentration when the Pyruvate, ADP, and Rodenone together solution was added?

Answer 1

1. There was no change in Oxygen concentration when Pyruvate only Solution was added because there was no ADP which could be phosphorylated to form ATP.

2. There was no change in Oxygen concentration when ADP only solution was added beacuse there was no fuel for the mitochondria (pyruvate) That could be oxydised to make ATP from ADP via Crebs Cycle.

3. There was a change in Oxygen concentration when ADP and pyruvate both were added because here pyruvate could be oxidised by Crebs cycle resulting in the functioning of electron transport chain and conversion of ADP to ATP in presence of Oxygen.

4. When rotenone only solution was added normally there was no change in oxygen concentration as there was no pyruvate or ADP and also rotenone is a blocker of ETC.

5. When pyruvate , ADP and rotenone together is added there no change in oxygen concentration because even if both Pyruvate and ADP is present, the presence of rotenone blockes the Electron transport chain prcicely It inhibits the transfer of electrons from iron-sulfur centers in complex I to ubiquinone, thus inhibiting ATP formation and consumption of oxygenby mitrochondria.