Role:

The citric acid cycle, also known as the tricarboxylic acid (TCA) cycle or Krebs cycle (after its discoverer in the year of 1937), is used to oxidize the pyruvate creating during the glycolytic breakdown of glucose into H₂O and CO₂.  It also oxidizes acetyl CoA arising from fatty acid degradation and amino acid degradation products. Additionally, the cycle gives precursors for several biosynthetic pathways.

Location:

The  citric  acid  cycle  operates  in  the  mitochondria   of  eukaryotes  and  in  the cytosol of prokaryotes. The Succinate dehydrogenase, the only membrane-bound enzyme   in the citric   acid   cycle   is embedded   in the inner   mitochondrial membrane in eukaryotes and in the plasma membrane in the prokaryotes.