CHM362H5 Lecture Notes - Lecture 8: Malate Dehydrogenase, Malic Acid, Mitochondrial Matrix
Document Summary
The overview of fatty acid synthesis: fatty acid chains are synthesized by acetyl-coa constantly adding 2-c units, the acetate units are activated by the formation of malonyl-coa which is a reaction that uses. Acetyl-coa + 7 malonyl-coa + 14 nadph + 13 h+ + h2o palmitate + 7 hco3. Both of these reagents in the cytosol are provided by the citrate-malate-pyruvate shuttle. For acetyl-coa: citrate is formed in the mitochondrial matrix and transported to the cytosol. Atp-citrate lyase converts citrate to oxaloacetate + acetyl-coa. It is made from nadh in 2 steps: malate dehydrogenase uses nadh to reduce oxaloacetate to malate, the malic enzyme oxidatively decarboxylates malate to make pyruvate and nadph. This reaction includes the carboxylation of acetyl-coa to form malonyl-coa. The enzyme used in this is acetyl-coa carboxylase (acc) This is an irreversible and committed step. Acc uses bicarbonate, atp, and biotin to do the job. The first reaction involves the carboxylation of biotin.
