FA & Lipid Metabolism

Question 1

What are the three sources of FA?

Answer 1

• Diet
• adipose storage
• Synthesis in tissue

Question 2

What are the 4 fates of FA?

Answer 2

1-Energy substrates
2-precursors
3-structural elements
4-signaling molecules

Question 3

What are chylomicrons?

Answer 3

Lipoproteins used to transport newly digested triacylglycerols

Question 4

What are the two ways FA are transported?

Answer 4

1-Carried by serum albumin (Free Fatty acids)

2-Lipoproteins

Question 5

What are the 4 classes of lipoproteins?

Answer 5

1-Chylomicrons (come from intestines with new FA)
2-VLDL (from liver to distribute lipids)
3-LDL (distribute lipids)
4-HDL (low triglycerides, collect lipids to take back to liver)

Question 6

What cells aid in cleaning up the vasculature and transfer lipids to HDL?

Answer 6

Foam cells (differentiated macrophages)

Question 7

What response does Glucagon elicit in adipocytes?

Answer 7

breakdown of triacylglycerol to Fatty acids

Question 8

What are triglycerides broken down to?

Answer 8

• Glycerol (enters glycolysis)

- Fatty acids (form acyl-coAs)

Question 9

Hos are fatty acyl-CoAs transported into the mitochondria?

Answer 9

Acyl-Carnitine/carnitine transporter

Question 10

What are the three stages of fatty acid oxidation

Answer 10

1-b-Oxidation
2-CAC
3-Oxidative phosphorylation

Question 11

What results from Fatty Acid B oxidation in the mitochondrial matrix?

Answer 11

Acetyl CoA which enters the CAC (FADH2 and NADH also produced)

Question 12

If acetyl CoA does not enter the CAC what does it form?

Answer 12

Ketone bodies :Acetone and a-B-hydroxybutyrate

Question 13

When there is excess Acetyl CoA, what is the general pathway?

Answer 13

Acetyl-CoA converts to Malonyl CoA and is added to another acetyl coA to make Polmitoyl CoA

Question 14

How does Acetyl CoA get to the cytoplasm(where lipid synthesis occurs) from inside the mitochodrial matrix?

Answer 14

The citrate shuttle

Question 15

What two moieties do you need to start fatty acid synthesis? (Fatty acid synthase acts on these)

Answer 15

1-Malonyl group

2-Acetyl group

Question 16

What biotin carried protein is responsible for malonyl-coA production?

Answer 16

Acetyl CoA Carboxylase

Question 17

NADPH is used for _________ Rxns. Wherease NADH is used for ________ rxns

Answer 17

Anabolic, Catabolic

Question 18

What 16 carbon Fatty acid is produced by lipid synthesis?

Answer 18

Pamitate (Palmyl-CoA)

Question 19

What enzyme is activated by insulin signal but deactivated by glucagon and is responsible for regulating the balance between FA synthesis and FA B-oxidation?

Answer 19

Acetyl-CoA Carboxylase (converts Acetyl-CoA to Malonyl-CoA for fatty acid synthesis)

Question 20

What is the precursor molecule for phospholipids and triglycerides?

Answer 20

phosphatidic acid

Question 21

What is cholesterol formed from?

Answer 21

Acetyl-CoA

Question 22

What are the 4 potential paths for cholesterol?

Answer 22

1-Hydroxysterols
2-Bile acids
3-CHolesteryl ester
4-Steroid hormones (ie. Cortisol, aldosterone, estradiol)

Question 23

What do cholesterol loaded foam cells become if damaged?

Answer 23

cholesterol rich atherosclerotic plaque in artery walls