Acronym for the tricarboxylic acid or
Kreb's cycle(after the Sheffield scientist who discovered it). It converts
citric acid, through a series of reactions to a four
carbon sugar, which is then acetylated back to citric acid again. In the process,
NAD and
FAD are reduced (as well as ADP and GDP phosphorylated) so that
oxidative phosphorylation can be carried out.
This not only provides reduced cofactors for the cell, but many amino acids are synthesised from the intermediates of the cycle.It is therefore the centre of the cell's metabolic net, with compounds feeding in and being taken out at all stages.