Biosynthesis of Fatty Acids Flashcards
A fatty acid consists of a hydrophobic hydrocarbon chain with a terminal carboxyl group that carries a negative charge at physiologic pH. This means that fatty acids are ________
amphipathic (having both a hydrophobic hydrocarbon tail and a hydrophilic carboxyl head
Almost all double bonds in fatty acids are in the _____ configuration.
cis
Biotin, serves as a cofactor for this enzyme
acetyl CoA carboxylase
Conversion of malonyl CoA into palmitate is done by ______
Fatty acid synthase
The product of fatty acid synthesis is ________
palmitic acid
Fatty acid synthesis occurs in the ______ of a cell
cytosol
fatty acid modification occurs in the ____ of the cell
Endoplasmic reticulum
The first two carbons in palmitic acid come from ________ , The rest of the carbons in the fatty acid all come from _______
acetyl CoA,
malonyl CoA
Enzymes in the ER, called _________, can desaturate fatty acids by introducing cis double bonds.
mixed-function oxidases
Prolonged consumption of a diet containing excess calories causes an increase in transcriptional expression of _______ and ________
acetyl CoA carboxylase,
fatty acid synthase
where does the fatty acid synthesis pathway start?
Acetyl CoA
what is the source of Acetyl CoA for F.A. synthesis
dietary carbohydrates, proteins or alcohol
where do the F.A synthesis reactions occur?
Citrate gets taken out of mitochondria so that it occurs in the cytosol
what is the rate limiting step in F.A. synthesis
acetyl CoA carboxylase
How is F.A synthesis regulated?
transcription: increased enzyme
substrate: amount of carbs and protein
citrate activates it
insulin dephosphorylates enzyme and activates it
