FA Synthesis

Question 1

ATP Citrate Lyase Function. What activates/inhibits it?

Answer 1

converts Citrate into Oxaloacetate and Acetyl CoA in the cytoplasm as part of the FA Synthesis. Activated by Insulin and Glucose. Inhibited by Leptin and PUFA.

Question 2

Acetyl CoA Carboxylase: function and inhibitors/activators.

Phosphorylation/Dephosphorylation states?

Answer 2

RATE Limiting Step in FA Synthesis. Converts Acetyl CoA into Malonyl CoA. Uses Biotin and CO2. Activated by Citrate and Insulin. Inhibited by Glucagon, Epinephrine, palmitate, PUFA, high AMP.

Active in the dephosphorylation state: Insulin via activation of phosphatase.
Inactive in the phosphorylation state: Epinephrine, Glucagon, AMP activate kinase A.

Question 3

Fatty Acid Synthase: function and inhibitors/activators

Answer 3

fatty acid synthesis to Palmitate. Inhibits Carnitine Acyltranferase (rate limiting step in FA degradation). It is activated by Insulin and Clucocorticoids and it is inhibited by PUFA.

Question 4

Where are Palmitates enlogated further? ( what location)

Answer 4

SER and Mitochondria. SER uses Malonyl CoA as C donor.

Mitochondria uses Acetyl CoA as C donor.

Question 5

Acyl CoA Desaturase: Function and location

Regulations of the enzyme

Answer 5

desaturates FA by introducing double bonds with the use of NADPH and O2. Occurs in SER.
FA with double bond beyond Carbon 9 and 10 cannot be synthesized in humans.

Gene expression induced by Insulin and Cholesterol. Inhibited by PUFA.

Question 6

Where does Fatty Acid Synthesis take place?

Answer 6

Liver mostly. Also in adipose tissues, kidney, brain, and mammary glands.

Question 7

What is the precursor of FA Synthesis? How many Carbons does it consist of?

Answer 7

Acetyl CoA. Has 2 Carbons

Question 8

Which enzyme does Malonyl CoA inhibits during FA Synthesis?

Answer 8

Carnitine Acyltranferase