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 |