| Comments |
"Mitochondria must respond quickly to changes in membrane potential and the penalty for any failure to do so is serious. The electron and proton transfers of chemiosmotic energy coupling generate a transmembrane potential of 150–200?mV [BNID 101102] over the membrane (~5?nm across), giving a field strength of about 30 million volt per metre, equal to that discharged by a bolt of lightning. This high membrane potential sets the inner membrane of bioenergetic organelles (mitochondria and chloroplasts) apart from all other eukaryotic membrane systems. Failure to maintain the mitochondrial membrane potential is penalized by a collapse in energy charge, blocking active transport across the cell membrane, and a rise in free-radical leak, which in eukaryotes and many prokaryotes leads directly to programmed cell death [ref 49]." See BNID 103680 |