Krebs cycle starts with the formation of a six-carbon compound by a reaction between

Step-by-step solution

Krebs cycle starts with the condensation of acetyl group from acetyl co-A with oxaloacetic acid (OAA) and water to yield citric acid. It has three carboxylic acid groups. Hence it is also called Tri Carboxylic Acid Cycle (TCA cycle). This reaction is catalysed by the enzyme citrate synthase and a molecule of CoA is released.