Carbon dioxide fixing reaction requires

Biotin-Independent Carboxylation ReactionsCarbamoyl phosphate synthetase, which isthe stepping stone for urea and pyrimidinesynthesis (Step 1, Fig. 14.13).Addition of CO2 to form C6 in purine ring.Malic enzyme, conveing pyruvate to malateGluconeogenesis1. Pyruvate Carboxylase ReactionPyruvate in the cytoplasm enters the mitochondria.Then, carboxylation of pyruvate to oxaloacetate is catalysed by a mitochondrial enzyme, pyruvate carboxylase (Fig. 9.24). It needs the co-enzymes biotin and ATP.Ref: DM Vasudevan Textbook of Medical Biochemistry, 6th edition, page no: 415