Q. No.Identify the correct statements regarding the mitochondrial electron transport system.
| I: | Electrons from NADH in mitochondrial matrix are first transferred to [Fe-S] and then to FMN in complex I. |
| II: | Complex II is not a proton pump. |
| III: | Cytochrome c is located on the outer surface of the inner membrane. |
| IV: | Ubiquinone, located within the inner mitochondrial membrane, is oxidized with the transfer of electrons to cytochrome c via complex III. |
| 1. | Only II and III | 2. | Only II, III and IV |
| 3. | Only IV | 4. | Only I and III |
In the electron transport system in the mitochondria, oxygen acts as a:
I: final acceptor of electrons
II: final acceptor of protons
| 1. | Only I | 2. | Only II |
| 3. | Both I and II | 4. | Neither I nor II |
Ubiquinone is:
| 1. | a protein in the mitochondrial electron transport chain |
| 2. | a substrate for synthesis of FADH |
| 3. | a vitamin used as coenzyme in Krebs cycle |
| 4. | a small hydrophobic coenzyme |
ATP synthase is located in the mitochondrial:
| 1. | matrix | 2. | electron transport chain |
| 3. | outer membrane | 4. | inner membrane |
ATP synthesis during oxidative phosphorylation in mitochondria is directly driven by:
| 1. | oxidation of glucose. |
| 2. | electron transport downhill in the ETC. |
| 3. | terminal transfer of electrons to oxygen. |
| 4. | chemiosmosis. |
When electron pass downhill in the ETC, the energy released is used to pump protons into:
1. matrix of mitochondria
2. cytosol
3. mitochondrial inner membrane
4. mitochondrial intermembrane space
Ubiquinone receives reducing equivalents via:
| I. Complex I | II. Complex II | III. Complex III |
| 1. | Only I | 2. | Only I and II |
| 3. | Only I and III | 4. | I, II and III |
Cytochrome c is found:
| 1. | attached to outer surface of the inner mitochondrial membrane |
| 2. | attached to inner surface of the inner mitochondrial membrane |
| 3. | in the inter membrane space |
| 4. | in the mitochondrial matrix |
The number of ATP molecules synthesized from oxidation of one molecule of NADH and one molecule of are respectively:
| 1. | 3 and 2 | 2. | 2 and 3 |
| 3. | 1 and 1 | 4. | 2 and 1 |
The stage of cellular respiration that directly involves oxygen is:
| 1. | glycolysis |
| 2. | at the end of ETC |
| 3. | Krebs cycle |
| 4. | the phosphorylation of ADP to form ATP |
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