Question

What accepts the electron after it passes through the second electron transport complex?

Answer 1

Electron transport system (ETS): Oxidative phosphorylation is referred to as the final step in cellular respiration occurring inside the mitochondria.

1. It is connected to the electron transport chain.
2. The electron transport system is located at the inner mitochondrial membrane.
3. The electrons are transferred from one member of the transport chain to another via a series of redox reactions taking place.
4. The major steps are as follows:
   1. Delivery of electrons via NADH and FADH2: Reduced NADH and FADH2 transfer their electrons that get oxidized to NAD+ and FAD and they are utilized in other steps of cellular respiration.
   2. Electron transport & Proton pump: The electrons start moving from a higher energy level to a lower energy level, thus releasing energy. This released energy is utilized to move the electrons from the matrix to the intermembrane space causing the development of an electrochemical gradient.
   3. Splitting of oxygen for water formation: The electrons then gets transferred to the oxygen molecule causing splitting into half and uptakes of H⁺ to form water.
   4. Synthesis of ATP: The hydrogen ions are passed through an enzyme called ATP synthase as it flows back into the matrix.
5. After complex II in the electron transport system, electrons are passed to ubiquinone and then further complex III, i.e. cytochrome bc1.