How does cyanide inhibit cellular respiration, specifically ATP synthesis?
It blocks the active site of the FeS-protein in complex 4.
Blast from the past, as I actually worked on this complex..
In the Electron Transport Chain involved in Oxidative Phosphorylation, electrons are shuttled between 4 protein cytochrome complexes. At least the last two, ComplexIII and ComplexIV, contain metal atoms.
Complex III (and, it seems, Complex IV) contains an Iron-Sulphur protein (also known as "Rieske"-protein), in which the iron-atom "oscillates" between the Ferric and the Ferrous states, facilitating temporary acceptance of the electron(s).
Cyanide(s) bind to this
This is literally a spanner in the works , and the result is that production of ATP stops.....