Define the proton motive force.
The proton motive force is a gradient of electrochemical potential across the inner
mitochondrial membrane created by the transport of protons, or hydrogen ions (H+),
from the mitochondrial matrix to the intermembrane space. This gradient is
established during oxidative phosphorylation and is crucial for ATP synthesis.
The electron transport chain, located on the inner mitochondrial membrane, pumps
protons from the matrix to the intermembrane space, generating a proton gradient.
The potential energy stored in the proton gradient is then harnessed by the ATP
synthase enzyme, which couples the movement of protons back into the matrix to
the synthesis of ATP.
The proton motive force is essential for the functioning of mitochondria, as it powers
the production of ATP through oxidative phosphorylation. Additionally, it is important
for various cellular processes, such as the transport of metabolites across the inner
mitochondrial membrane and the maintenance of mitochondrial membrane potential.
Defects in the proton motive force have been linked to various diseases, including
mitochondrial disorders and neurodegenerative diseases. Thus, understanding the
mechanisms underlying the formation and regulation of the proton motive force is
critical for both basic and applied research.
References:
1. Nicholls, D. G., & Ferguson, S. J. (2013). Bioenergetics (4th ed.). Academic Press.
2. Klingenberg, M. (2008). The ADP and ATP transport in mitochondria and its carrier.
Biochimica et Biophysica Acta (BBA) - Bioenergetics, 1778(10), 1978-2021.
3. Finkel, T. (2012). Signal transduction by mitochondrial oxidants. Journal of Biological
Chemistry, 287(7), 4434-4440.