Pyruvate into Oxaloacetate

1)CO2 activation - Bicarobnate + ATP into Carboxyphosphate + ADP
- This step can only take place in the presence of acetyl CoA
2)Biotin carboxylation - Carobxyphosphate + BiotinEnzyme into CO2-biotin-enzyme + Inorganic Phosphate
- Biotin is not carboxylated unless acetylCoA is bound to the enzyme
- Allosteric activation
3)CO2-BiotinEnzyme cleavage - CO2-BiotinEnzyme + Pyruvate into BiotinEnzyme + Oxaloacetate
- Long flexible link between biotin and enzyme enables the carboxybiotin to rotate form one active site
- Avtivated group is then transfered from CO2Biotin to Oxaloacetate

Van Castillo