The document summarizes the electron transport chain (ETC), which involves NADH transferring electrons through a series of components - including coenzyme Q, cytochromes b, c, a, and a3 - via oxidation-reduction reactions. This electron transfer through the components of the respiratory chain generates energy in the form of ATP. Finally, oxygen acts as the most electronegative final electron acceptor, producing a molecule of water.

1. Unit II
Electron Transport Chain
Isha Rani
(Assistant Professor)
MMCP, MMU-Mullana

2. Respiratory chain (ETC)
• NADH2 is produced in kreb cycle from NAD+
• NADH2 transfer of hydrogen to respiratory chain where electron is
transported in a series of oxidation and reduction steps which reacts
with molecular oxygen.

3. Components of Respiratory Chain
• Coenzyme Q
• Cytochromes (b,c,a,a3)
• Molecular Oxygen

4. Electron Transport Chain

5. Steps:
NADH2 is oxidized by coenzyme Q, then produce enough energy for
the synthesis of Atp by oxidation process.
Coenzyme Q is oxidized by cytochrome b.
Cytochrome b is oxidized by cytochrome c and produced enough
energy for synthesis of ATP by oxidation process.
Cytochrome c is oxidized by cytochrome a,a3 and produced enough
energy when cytochrome a is oxidized by oxygen atom and electron
arrive at bottom of respiratory chain.

6. • O2 is most electronegative substance and final acceptor of electrons.
A molecule of water is produced.

7. Thank You