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Biochemistry II exam II > Liposys > Flashcards

Flashcards in Liposys Deck (61):
1

What mobilizes the fatty acid (FA) from triglycerides?

Lipases

2

What activate the FA's?

Acyl CoA synthetase
Pyrophosphatase

3

What stimulates AMPK?

Glut4
Glycogen breakdown
Glycolysis
LPLm Activation
Fat burning

4

What inhibits AMPK?

Cholesterol synthesis
Glycogen synthesis
TAG synthesis
Fatty Acid Synthesis

5

What does Insulin do?

De-phosphorylates and deactivates HSL
Inhibits ATGL

6

What is the fate of glycerol?

transported in blood to lvier

7

What happens to glycerol in the liver?

phosphorylated to glycerol-3-phosphate

8

When Glycerol is turned into G3P in the liver what can happen to it?

TAG synthesis
Phospholipid synthesis
DHAP (glycolysis, gluconeogenesis)

9

What tissues are Free FA's sent to?

Skeletal muscle, heart, renal cortex
Fuel source

10

How are free fatty acids transported in the blood?

by being bound to serum albumin

11

How many Free FA's can albumin carry?

up to 10 free fatty acids per protein monomer

12

What does it mean to activate a Fatty acid?

to turn a FA into Acyl CoA

13

What is the process of FA degradation?

1. enters the muscle
2. Fatty acid is activated
3. FA enters the mitochondria
4. Fa is oxidized in mitochondria (OX,Hydration, OX, Thiolysis)

14

What is a Chaperone protein?

a protein that escorts the FA (Ex: FABPc)

15

What enzyme activates a FA?

Acyl CoA synthetase

16

When is a FA acid ready to enter the mitochondria?

After being activated (it's now "acyl-CoA)

17

What drives the activation of a FA?

ATP

18

what is the location of FA activation?

Outer mitochondrial membrane

19

During activation of the fatty acid what is ATP turned into?

AMP +PPi

20

What is the significance of PPi in fatty acid activation?

pyrophosphate (PPi) is hydrolyzed making the reaction irreversible

21

When PPi is hydrolyzed what do we get?

2Pi and energy

22

What does the Carnitine Palmitoyltransferase (CPT) complex consist of?

CPT 1
Acylcarnitine translocase (aka: canitine acyltransferase 1)
CPT II

23

What is Carnitine PalmitoylTransgerase (CPT) complex responsible for?

transport of LCFAs

24

What is the rate limiting step in lyposis?

CPT 1 (part of CPT complex)

25

What is CPT complex reversibly inhibited by?

Malonyl-CoA
(involved in the 1st committed step in FA synthesis)

26

At what pH does CPT complex work most effectively?

at a Neutral PH

27

With what decrease in pH does CPT complex stop working?

Cpt 1 is inhibted from a ph decrease 7.0->6.8

28

What does Beta oxidation refer to?

the four steps that occur prior to having fat enter the aeroboic system (OHOT)

29

What is OHOT?

Oxidation
Hydration
Oxidation
Thiolysis

30

What enzyme drives the first Oxidation in OHOT?

Acyl CoA dehydrogenase

31

What enzyme drives Hydration in OHOT?

Enoyl CoA hydratase

32

What enzyme drives the second oxidation in OHOT?

L-3 hydroxyacyl CoA dehydrogenase

33

What enzyme drives the Thiolysis in OHOT?

Beta-ketothiolase

34

What are the products of beta oxidation?

FADH2 and NADH
Acetyl CoA
Fatty acid "minus two"

35

What is the product of Acyl CoA dehydrogenase?

oxidation (what the enzyme does) produces a double bond and FADH2

36

What does Enoyl CoA hydratase do?

adds a hydroxyl group and removes a double bond

37

What is the product of L-3 hydroxyacyl CoA?

oxidation turns the hydroxyl group into a carbonyl (the hydroxyl group was formed from Enoyl CoA hydratase)

38

Where does the Acetyl CoA formed in Beta-oxidation go?

it enters the Krebs cycle to produced FADH2 and NADH to be sent to the ETS

39

What are the two additional enzymes required when we have an Unsaturated FA?

2,4-dienoyl CoA Reductase Isomerase

40

What additional enzymes do Polyunsaturated FA need?

If odd numbered Double bonds just Isomerase.
If even numbered double bonds, reductase and isomerase.

41

For Beta-Oxidation of Unsaturated FA's and even numbered FA's what is the order of reactions?

ORIOT (Oxidation Reductase Isomerase Oxidation Thyolysis)

42

what is the different product of odd-chain fatty acids?

propionyl CoA

43

What is the product of odd-chain fatty acids, propionyl CoA, turned into?

Succinyl CoA

44

If energy is required in the Liver what occurs in mitochondria for FA oxidation regulation?

Beta oxidation

45

If energy is not needed from the liver during FA oxidation regulation, what happens?

TAG and phospholipids in cytosol are formed

46

When there is a High NADH/NAD+ ratio what is giving off to stop which oxidation step in OHOT?

signal high energy
Inhibits 2nd oxidation step (3-hydroxyacyl CoA dehydrogenase)

47

What does a High concentration of Acetyl CoA inhibit?

inhibits thioase

48

For FA oxidation regulation, what does an increase in glucose do?

increases malonyl CoA
inhibits CPT I and Inhibits Beta-oxidation

49

For FA oxidation regulation, an increase in AMP concentration from fasting or excercising cause what?

AMPKinase (activation)
Stimulates FA oxidation
Inhibits FA synthesis

50

What are the hormone(s) that stimulate FA oxidation?

epinephrine
Norepinephrine
Glucagon

51

What stimulates FA oxidation ?

Hormones
AMP (cAMP)
Low energy

52

What hormone(s) inhibit FA oxidation?

Insulin

53

What inhibits FA oxidation?

Hormones (insulin)
High glucose
high energy
high NADH/NAD+
Malonyl Coa

54

What are the key enzymes in FA oxidation?

Lipases
Acyl CoA synthetase
Acyl CoA dehydrogenase

55

what do lipases do?

frees fatty acids from tyiglycerids

56

what does Acyl CoA synthetase do?

Activates the Fa for transport into the mitochondria

57

What are the steps in FA oxidation?

1. mobilize the FA from triglyceride (Lipases)
2. Bring FA to the mitochondria
3. Activate FA
Transport the FA into the matrix of mitochondria
4. Beta Oxidation (OHOT or ORIOT)
5. Enter the aerobic system (Krebs and ETS)
6. Make ATP

58

What is HSL strongly inhibited by?

Insulin

59

Muscle adipose triglyceride lipase (ATGL) is significantly elevated in who?

type 2 diabetics

60

HSL (hormone sensitive lipase) skeletal muscle protein content is significantly reduced and heavily inhibited in who ?

type 2 deabetics

61

Hormone sensitive lipase (HSL) exibits a 10-fold higher specific activity for what?

DAG rather than TAG