Fatty Acid Synthesis Flashcards
Where does fatty acid synthesis occur?
in the cytosol or cytoplasm
The building block of fatty acids is
acetyl CoA
Where is acetyl CoA produced?
in the matrix of the mitochondria
What rxn begins fatty acid synthesis?
irreversible carboxylation of acetyl CoA
What does the carboxylation of acetyl CoA result in?
generates malonyl CoA and commits the acetyl group to fatty acid synthesis
What enzyme and cofactor catalyze the carboxylation of acetyl CoA?
acetyl CoA carboxylase and biotin
What factors promote the process of fatty acid synthesis?
High levels of citrate and ATP
What 3 things does every carboxylase require?
- an energy source (ATP)
- a carbon source (HCO3-)
- a cofactor( biotin, i.e. vitamin B7)
What is the rate limiting step of the entire rxn?
the conversion of acetyl CoA to malonyl CoA
Which enzyme is regulated to either inhibit or activate fatty acid synthesis?
acetyl CoA carboxylase
ACP means …
Acyl Carrier Protein
What does FAS stand for and what does it do?
Fatty acid synthase and it is an enzyme that catalyzes all the 7 steps of fatty acid synthesis
Describe FAS
a single polypeptide chain that contains 7 different catalytic sites and domains as well as an ACP domain
Describe ACP
contains a phosphopantetheine group which contains a sulfhydryl group which allows the binding of certain molecules
Step 1
- catalyzed by acetyl transacylase
2. acetyl CoA attaches to sulfhydryl of ACP and an intermediate is formed