What is the role of the electron transport chain in mitochondria?
The electron transport chain (ETC) is a crucial component of the aerobic respiration
process that occurs in the mitochondria of eukaryotic cells. It plays a vital role in the
final stage of cellular respiration, known as oxidative phosphorylation, which enables
the production of ATP, the energy currency of the cell.
During the ETC, electrons from NADH and FADH2, which are produced earlier in the
respiration process, are passed down a chain of electron carrier molecules. The
energy released from the electron transfer is used to actively transport protons (H+)
across the inner mitochondrial membrane from the matrix to the intermembrane
space, generating a proton gradient. This gradient generates a proton motive force
that drives ATP synthesis via chemiosmosis.
The final electron acceptor in the ETC is oxygen, which eventually combines with
protons and electrons to form water. This makes oxygen an essential component of
cellular respiration, as without it, the ETC cannot function correctly, and the
production of ATP would be severely reduced.
Overall, the electron transport chain is an essential process in the synthesis of ATP,
allowing cells to generate the energy required for normal metabolic processes and
physiological functions.
References:
1. Lodish, H., Berk, A., Zipursky, S. L., et al. (2000). Molecular Cell Biology. 4th edition.
Section 14.4, Mitochondria and Chloroplasts. W. H. Freeman.
2. Nicholls, D. G., & Ferguson, S. J. (2013). Bioenergetics 4. Academic press.