6. Fatty acids are activated on the outer membrane of mitochondria Fatty acids are converted to fatty acyl-CoA(a high energy compound) via a fatty-acyl-adenylate intermediate(enzyme-bound, mixed anhydride) by the action of fatty acyl-CoA Synthetases(also called fatty acid thiokinase Pyrophosphate is hydrolyzed by inorganic pyrophosphatase, thus two anhydride bonds of aTP are consumed to form one high-energy thioester bond, thus pulling the reaction forward: a common phenomena in biosynthetic reactions Acyl-adenylates are often formed when-COoH groups are activated in biochemistry
6. Fatty acids are activated on the outer membrane of mitochondria • Fatty acids are converted to fatty acyl-CoA (a high energy compound) via a fatty-acyl-adenylate intermediate (enzyme-bound, mixed anhydride) by the action of fatty acyl-CoA synthetases (also called fatty acid thiokinase). • Pyrophosphate is hydrolyzed by inorganic pyrophosphatase, thus two anhydride bonds of ATP are consumed to form one high-energy thioester bond, thus pulling the reaction forward: a common phenomena in biosynthetic reactions. • Acyl-adenylates are often formed when –COOH groups are activated in biochemistry
Fatty acyl-CoA is formed from fatty 0-P-0-P-0-P-0-Adenosine acids and coenzyme A via a fatty acyl- R-C Fatty acid AMP intermediate fatty acyl-CoA synthetase 0-P-0- Adenosine O-P_0-P-0+ R-C Fatty acyl-adenylate (enzyme-bound) O Pyrophosphate COA-SH fatty acyl-CoA Inorganic synthetase AMP pyrophosphatase 2P R一 Fatty acyl-CoA S-CoA △G°=-33.4kJ/mol △G°=0.9kJ/mol (for the two-step process)
Fatty acyl-CoA is formed from fatty acids and coenzyme A via a fatty acylAMP intermediate