Fatty acid metabolism

Question 1

What is the difference in FA transport between the fed state and fasted state?

Answer 1

Fed state: transported as part of a TAG in lipoproteins

Fasted state: FA bound directly to albumin

Question 2

What are the two essential fatty acids?

Answer 2

Linoleic (18:2 [9,12]) and linolenic (18:3 [9,12,15) acids

Question 3

Where must acetyl groups be in fatty acid biosynthesis, and how do they get there?

Answer 3

They must be in the cytoplasm; carried by citrate (which also activates acetyl CoA carboxylase)

Question 4

Acetyl CoA carboxylase

Answer 4

Rate-limiting enzyme; catalyzes formation of malonyl CoA

Question 5

Fatty acid synthase complex

Answer 5

Utilizes one acetyl coA and 7 malonyl coA to form even-numbered, saturated fatty acids

Question 6

What two cofactors are needed for fatty acid biosynthesis?

Answer 6

Biotin and NADPH

Question 7

Short term allosteric activator of fatty acid synthase complex

Answer 7

Fructose 1,6 BP

Question 8

Overall reaction for fatty acid synthesis

Answer 8

1 Acetyl CoA + 7 Malonyl CoA + 14 NADPH + 14H+ -> palmitate + 7 CO2 + 14 NADP+ + 8 CoA + 6 H2O

Question 9

Where does fatty acid synthesis occur?

Answer 9

On the FAS complex

Question 10

Peroxisome proliferator-activated receptors

Answer 10

Promote TAG deposition

Question 11

Where is most glyceraldehyde 3-P obtained?

Answer 11

From glyceroneogenesis through precursors such as alanine, pyruvate, and lactate