Lipid Oxidation Flashcards

1
Q

what does gall bladder do

A

emulsify fat into little lipid drolplets to make them more accesible to lipases which break them down into individual FA’s and reincorporated into triglycerides and put into a chilomicron

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Where do chilomicrons tracel

A

blood vessels and lymph to deliver FA’s through lipo protein lipase which is activiated by insulin which helps break down FA’s and allow them to be absorbed. Glycerol goes back into bloodstream to be reabsorbed. through

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What is B-48

A

protein component of chylomicron recognized by lipoprotein lipase.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What are the major classes of human plasma lipoproteins

A
  1. chylomicrons
  2. VLDL
  3. LDL
  4. HDL
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Which two lipoproteins have the highest amount of triacylglycerols

A
  1. Chylomicrons; dietary lipid

2. VLDL; lipid from liver

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is ApoB-100

A

What LDL receptors bind to and bring it in; if you have a mutation in LDL receptor you get problems with cardiovascular system

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What is LCAT

A

enzyme that HDL uses this when it scavengers cholesterol from bloodstream.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What activates LCAT

A

Apo A

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What are the apolipoproteins

A
  1. Apo A
  2. Apo B-100: Ligand for receptor
  3. Apo B-48: structural role
  4. Apo C-II; Activator of lipoprotein lipase
  5. Apo E: ligand for receptor
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What are the principal enzymes in lipoprotein metabolism

A
  1. LCAT
  2. Lipoprotein lipase (LPL
  3. Hepatic lipase
  4. acid lipase
  5. MTP
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What activates uptake of fat from chylomicrons

A

lipoprotein lipase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What are healthy levels LDL and HDL

A

LDL: 40 mg/dL mdn

>50 mg/dL women

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

WHat are healthy cholesterol levels

A

<200

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What is healthy level of triglycerides

A

<100-150

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Where are lipoprotein lipases found

A

found on endothelial cell surface, mostly around adipose, heart and skeletal muscle

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

what activates lipoprotein lipase

A

insulin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Glycerol remains in bloodstream and is ____to liver for _____

A

recycled; gluconeogenesis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What hormone is released when we’re fasting to release free fatty acids and glycerol

A

Hormone sensitive lipase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

what are perilipins

A

keep lipid droplet in adipocyte in tact and prevent release of triglyceride prematurely.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What does hormone sensitive lipase do

A

cleave off individual FA from triglyceride and release it into the bloodstream

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What are two targets of protein kinase A

A

perilipins and hormone sensitve lipase

22
Q

Describe fatty acid activation

A
  1. convert FA to acyl coA derivatives using Acyl CoA synthetase
23
Q

Conversion of FA to an activated acyl derivative requires ____high energy phosphate bonds

A

2

24
Q

FA must be activated to ____in order to be transported into the mitochondria to initiate ____

A

FACoA; beta oxidation

25
Q

What is carnitine

A

Derived from lysine; carrier for lipids; transports fatty acyl-CoA into mitochondria for oxidation

26
Q

What happens when you have carnitine deficiency? What if you have too much of it?

A

hypoketotic hypoglycemia-cant oxidize fat so losing out on production of energy;
too much results in conversion to TMAO by gut flora which promotes atherosclerosis

27
Q

What does carnitine acyltransferase 1 do

A

Swap CoA carrier to carnitine carrier–> fatty acyl carnitine transfers fatty acyl carnitine in and free carnitine back out.

28
Q

What does carnitine acyltransferase II do

A

Converts FA from carnitine back to fatty acyl CoA

29
Q

What does malonylCoA inhibit

A

CAT 1 which prevents futile cycle of FA breakdown and synthesis happening simultaneously

30
Q

What is the first stage of fatty acid oxidation

A
  1. Beta oxidation: NADH and FADH2 made go to electron transport chain. Acetyl CoA go to TCA cycle
31
Q

What happens during beta oxidation

A
  1. Dehydrogenation: Make a keto group on beta carbon by converting single bond to DB by degydrogenation. H’s then get donated to FAD to make FADH2 to go into electron transport chain.
  2. Hydrate DB to make hydroxyl group by using NAD to make NADH to go to ETC
  3. Cleave by thialase to reduce the length of chain to make new fatty acyl CoA and released an acetyl CoA which goes to TCA cycle
32
Q

How many cycles does it take for beta oxidation

A

7

33
Q

what is the yield for palmitate

A

8 Acetyl CoA
7 NADH
7 FADH2

34
Q

How many ATPs can you make from oxidation of fat

A

129

35
Q

What is the deficiency in medium chain Acyl CoA dehydrogenase

A

Most common defect in fat metabolism; genetic disorder in infants causes fasting hypoglycemia. Dont have energy from fat being produced.

36
Q

Most FA contain ___DB, but in oxidation we produce____DB. Unsaturated fatty acids cause decrease in ATP produced because you have to use energy to move DB around to change its configuration.

A

cis; trans

37
Q

Oxidation of odd-chain FA can produce what?

A

Only release acetyl CoA and 3 carbon compound -1 Propionyl CoA which can be converted to succinyl CoA which goes into TCA cycle to form oxaloacetate. This can form glucose!

38
Q

Rate limiting step of FA oxidation

A

Transport of fats into mitochondria

39
Q

What are the steps of FA synthesis

A
  1. High blood glucose activates insulin
  2. Phosphatase removes phosphate groups on acetyl CoA carboxylase and activates it.
  3. Low blood glucose activates glucagon which activates protein kinase A which phosphorolates acetyl CoA carboxylase and inactivate it.
40
Q

What can block CAT 1

A

malonyl CoA; so we cant hook FA to carnitine carrier to get it into mitochondria

41
Q

Fatty acid oxidation occurs in all tissues except ___ and ____

A

brain and erythrocytes

42
Q

Where does FA oxidation occur

A

mitochondrial matrix

43
Q

What does FA oxidation require

A

acetyl CoA, FAD, and NAD+

44
Q

What is FA oxidation inhibited by

A

malonyl CoA

45
Q

When does FA occur

A

low energy state (high ADP) and during fasting. (high glucagon)

46
Q

Where does FA synthesis occur

A

in liver and adipose in cytosol

47
Q

What is required for FA synthesis

A

Acetyl CoA, NADPH, malonyl CoA

48
Q

What activates FA synthesis

A

citrate

49
Q

What is FA synthesis inhibited by

A

long chain acyl CoA

50
Q

When does FA synthesis occur

A

high energy state. Lots of ATP present; Usually after carbohydrate feeding. (high insulin)