Fatty acid synthase action Flashcards
What is the first part of the first step of FA biosynthesis?
Reaction between Biotin and HCO3 -
What is the useful product formed via the reaction between biotin and HCO3 -?
Biotin-CO2
What enzyme is used in the second part of the first step of fatty acid biosynthesis?
Transcarboxylase
What is the second step of fatty acid biosynthesis?
Chain elongation
How are long chain fatty acids formed?
Additions of acetyl-CoA and malonyl-CoA
Role of acetyl-CoA in chain extension?
Primes the reaction, and becomes the methyl terminus of the fatty acid chain
Role of malonyl-CoA in chain extension?
Each one provides a 2 carbon unit to extend the chain
What is needed for chain extension other than acetyl-CoA and malonyl-CoA?
NADPH and H+
How many NADPH and H+ are needed per malonyl-CoA?
2
Overall reactants for FA biosynthesis (combining steps)?
acetyl-CoA, ATP, NADPH and H+
Reactants for formation of palmitate?
8 acetyl-CoA, 7 ATP, 14 NADPH and 14 H+
Why is 8 acetyl-CoA needed for the formation of palmitate?
1 is needed for the methyl terminus of palmitate, the other 7 are used to make 7 malonyl-CoA
Why is 7 ATP needed for the formation of palmitate?
It is used to make 7 malonyl-CoA from 7 acetyl-C-A
What happens to the CO2 used in the first step of FA biosynthesis?
It is replenished as the second step produces the same amount of CO2 that the first step uses
What are the overall products of FA biosynthesis (combining steps)?
FA, CoA, H20, ADP, PI, NADP+
Overall products of palmitate formation?
palmitate, 8 CoA, 6H2O, 7 ADP, 7 PI and 14 NADP+
What catalyses the second step of FA biosynthesis?
Fatty acid synthase