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Flashcards in Cholesterol Synthesis Deck (46):
1

What is cholesterol located between

Membrane fatty acid chains

2

What does cholesterol form

Loose cross links and reduce fluidity

3

By forming loose cross links and reducing fluidity what is increased

Increases rigidity if cholesterol is next to a saturated LCFA

4

Where is cholesterol the highest in

Plasma membranes and is virtually absent from inner mitochondrial membranes

5

What is cholesterol a precursor to

Bile salts
Steroid hormones

6

esterfied LCFA attached to hydroxyl group and only 30% occurs in the free form

Esterfied cholesterol

7

Esterfied cholesterol form

Hydrophobic

8

Where is esterfied cholesterol not located

Membranes

9

What's esterfied cholesterol transported by

Lipoproteins

10

What is solubilized in bile

Esterfied cholesterol

By bile salts and phospholipids

11

Any common organic molecule produced by combing an acid with an alcohol

Ester

12

Cholesterol primary site

Liver
Extrahepatic tissues:
Intestine adrenal cortex reproductive tissues

13

Cholesterol location

Cytosol
Some enzymes are bound to the ER

14

What are the raw materials

Carbon atoms: Acetyl CoA
Reducing power: NADPH
Energy: ATP Thioester cleavage

15

Carbs proteins and fat to Acetyl CoA to?

Cholesterol

16

Synthesis of Mevalonic Acid: 3 hydroxy 3 methyglutsryl CoA

HMG CoA NEEDS NADPH AND ATP

17

What is the rate limiting enzyme

HMG CoA reductase

18

HMG CoA reductase reactions occurs in the

Cytosol

19

What is cholesterol a essential component of

Cell membranes

20

what enzyme creates mevalonate

HMG CoA Reductase

21

what is the first unique compound in cholesterol?

mevalonate

22

what is irresversible

HMG CoA Reductase

23

Regulation is active when

non phosphorylates

24

regulation is inactive when

phosphorylated

25

squalene is originally in what type of shape

in a straight line and needs to get to a ring structure

26

where are the primary bile acids made

in the liver and secreted into the duodenum

27

where are the secondary bile acids made

in the intestine and bacterial enzymes act on the primary bile salts

28

bile salts/acids are secreted as

cholesterol

29

bile acids/salts are both

polar and nonpolar and emulsified in the intestine

30

bile acids/ salts are what kind of steroid nucleus

saturated steroid nucleus

31

what is the difference?

the number and position of the hydroxyl groups
all hydroxyl groups have an alpha configuration

32

what happens at the physiological ph

they ionize and occur as sodium and potassium salts

33

name the primary bile salts

glycocholic
taurocholic
glycochenodeoxycholic
taurochenodeoxycholic

34

name the secondary bile salts

deoxycholic
lithocholic

35

what is the precursor for all steroid hormones

pregnenolone

36

eat carbs
muscle and liver are full of energy and glycogen
glucokinase pushes glycolysis forward to liver
prep step runs
starts the krebs
citrate is kicked out
citrate lyase gives back the acetyl CoA
makes fat and cholesterol

cholesterol story

37

sterol dependent

low sterol levels stimulate HMG COA reductase increased synthesis

38

sterol dependent

high sterol levels in the cell down regulates cholesterol synthesis

39

sterol accelerated

degradation of HMG COA reductase

40

sterol independent

AMP activated protein kinase (activated by CAMP)
reductase phosphorylated- inhibited

41

hormonal regulation stimulation

thyroxine and insulin

42

hormonal regulation and down regulation

glucagon and glucocorticoids

43

statins are ...to HMG COA reductase

competitive inhibitors

44

is there degradation of cholesterol

no

45

cholesterol synthesis is stimulated by

ATP
NADPH
insulin
fructose

46

cholesterol synthesis is inhibited by

ADP
AMP
NADP
glucagon