<prompt> In TCA cycle, citrate is conveed into cis-aconitate by which mechanism?Loss of HLoss of phosphateLoss of H2O moleculeLoss of carbon dioxide molecule  <response>: 2nd Step: Formation of Isocitrate, Citrate is isomerized to isocitrate by aconitase Step 2, Fig.18.2. This reaction is a two-step process. At first, one water molecule is removed from citrate forming cis aconitate; a transient compound with a very sho half-life. Immediately, one water molecule is added to aconitate to form isocitrate. Thus the position of the hydroxyl group is shifted.Ref: DM Vasudevan, 7th edition 