cellular respiration

Question

1.  List the components of the electron transport chain in order of increasing 

            electronegativity

Answer 1

The electron transport chain (ETC) is a series of protein complexes and electron carriers located in the inner mitochondrial membrane. Electronegativity is a measure of an atom's ability to attract electrons. In the context of the ETC, the electron carriers generally become more electronegative as electrons move through the chain. Here are the main components of the electron transport chain in order of increasing electronegativity:

1. NADH and FADH2:
2. Electrons enter the ETC from these electron carriers. They are relatively less electronegative.
3. Complex I (NADH dehydrogenase):
4. The first protein complex in the electron transport chain. It receives electrons from NADH.
5. Coenzyme Q (Ubiquinone):
6. A mobile electron carrier that transfers electrons from Complex I to Complex III.
7. Complex II (Succinate dehydrogenase):
8. This complex is involved when FADH2 donates electrons directly to the electron transport chain.
9. Cytochrome c:
10. A small heme protein that carries electrons from Complex III to Complex IV.
11. Complex III (Cytochrome bc1 complex):
12. This complex is involved in the transfer of electrons from Coenzyme Q to Cytochrome c.
13. Cytochrome c oxidase (Complex IV):
14. The final complex in the electron transport chain. It transfers electrons to molecular oxygen, forming water.

As electrons move through the electron transport chain, they generally move from carriers with lower electronegativity to carriers with higher electronegativity, ultimately leading to the reduction of oxygen to water. This flow of electrons generates a proton gradient, driving ATP synthesis through chemiosmosis. Keep in mind that the actual electronegativity values of these components may vary, but this order provides a general trend in terms of increasing electronegativity along the electron transport chain.