Molecular Fundamentals - Fatty Acid Synthesis

what is the only fatty acid that our bodies can synthesize?

palmitate

fatty acids are synthesized mainly where?

in the liver

fatty acid synthesis occurs in what part of the liver?

cytoplasm

Acetyl CoA cannot cross the mitochondrial membrane so it must be converted to what?

citrate

what are the four things needed for fatty acid synthesis to occur?

• fatty acid synthase

• NADPH

• Acetyl CoA

• Malonyl-CoA

citrate leaves the mitochondria is converted to what by citrate lyase?

oxaloacetate and Acetyl CoA

citrate is converted to oxaloacetate and Acetyl CoA in the cytoplasm by what?

citrate lyase

once oxaloacetate is converted to malate, malate is converted to pyruvate by what?

malic enzyme

when malic enzyme converts to malate to pyruvate, what is produced?

NADPH (because malic enzyme has a higher affinity for NADP+ than NAD+)

glucose can produce NADPH through what?

pentose phosphate pathway

acetyl CoA gets converted to Malonyl-CoA by what?

acetyl CoA Carboxylase/Biotin

acetyl CoA Carboxylase/Biotin does what?

converts acetyl CoA to Malonyl-CoA

what do fatty acids use to enter the mitochondria to produce energy?

carnitine palmitoyltransferase I

Malonyl-CoA inhibits what?

carnitine palmitoyltransferase I

CoA in the cytoplasm of the liver comes from what?

ribose-5 phosphate that is produced from the pentose phosphate pathway

what enzyme combines the ACP hand of the fatty acid synthase with acetyl-CoA?

acetyl transacylase

what enzyme moves the two carbons from the ACP hand of the fatty acid synthase to the cyst hand?

acyl transacylase

what enzyme combines the ACP hand of the fatty acid synthase with malonyl-CoA?

malonyl transacylase

what are the four most important steps of fatty acid synthesis?

• condensing

• reductase

• dehydratase

• reductase

energy generated from what step allows ACP to keep the carbons, instead of giving them to cyst?

condensing (enzyme: acyl malonyl ACP condensing enzyme)

acyl malonyl ACP condensing enzyme causes the complex to do what?

loses a carbon

β-Ketoacyl ACP reductase uses what to reduce the β-Ketone on the chain?

NADPH (produces NADP+)

3-hydroxyacyl dehydratase does what?

removes H₂O from the chain

enoyl ACP reductase uses what to reduce the enoyl on the chain?

NADPH (produces NADP+)

what enzyme removes the palmitate from the fatty acid synthase?

thioesterase

you repeat the steps of fatty acid synthase until what?

you reach the amount of carbons (16 carbons) needed for palmitate

what kind of fatty acids are formed in the body?

nonessential fatty acids

what kind of fatty acids cannot be formed in the body?

essential fatty acids

essential fatty acids must be what?

supplied by the diet

humans cannot introduce double bonds past what position?

9 in the fatty acid chain (start at acid group when counting)

how do you determine what omega the unsaturated chain is?

count the number of carbons until you reach the first double bond, starting from the omega end

what is the metabolic process that breaks down fatty acids to generate energy called?

beta oxidation