Lecture 30 Lipids II

Question 0

Where in cell are components located for FA synthesis?

Answer 0

cytoplasm

Question 1

FA synthesis occurs primarily where? Secondarily?

Answer 1

primarily in liver

also in brain, kidneys, adipose tissue

Question 2

what is the RLS of FA synthesis and what enzyme catalyzes this step?

Answer 2

Acetyl CoA –> Malonyl CoA

(Acetyl CoA Carboxylase) ACC via carboxylation

ACC adds CO2 to acetyl CoA

Question 3

What are the steps in FA synthesis

Answer 3

1) Formation of Acetyl CoA
2) Conversion of Acetyl CoA –> Malonyl CoA
3) Elongation
4) Desaturation

Question 4

Where do the reactions of FA synthesis occur?

Answer 4

Fatty Acid Synthase Complex

Question 5

Fatty Acid Synthase (FAS) characteristics

Answer 5

multi-enzyme, 2 identical dimers (260 kDa) each, has 7 catalyitc enzymes
acyl carrier protein (ACP) with PP
dimers arranged head to tail with PP of one arranged with cysteinyl sulfhydryl group of another

Question 6

FA synthesis

Answer 6

Condensation
Reduction
Dehydration
Reduction

Question 7

Synthesis of very low density lipoproteins (VLDL)

Answer 7

VLDL B100

B48 in chylomicrons

Question 8

Cholesterol Biosynthesis RLS

Answer 8

Acetyl CoA –> Mevalonate

in cytoplasm
Enzyme is: HMG CoA Reductase (target of statins)

Question 9

eiconosoids

Answer 9

Prostaglandin E2
Prostacyclin PGI2
Thromboxane A2
Leukotriene B4

Question 10

ACC Regulation

Answer 10

(+) citrate, insulin, high carb/low fat (induction)

(-) long chain FA, glucagon, epinephrine, low carb/high fat

Question 11

How much cholesterol produced in body

Answer 11

1 g/day, mostly in liver

Question 12

Where does LDL occur and what does it carry?

Answer 12

liver, B100