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Flashcards in fat synthesis Deck (104):
1

3 questions to ask

do you have enough energy
do you have enough stored carbs
what should i do now

2

Fatty acid synthesis

you build fatty acids when you consume excess carbs

3

when dont you build fatty acids

when you consume excess fats

4

how does glucose get in the cell

it does not diffuse in the cell directly
2 transport mechanisms

5

what are the 2 transport mechanisms for getting glucose into the cell

sodium independently facilitated transport system
sodium monosaccharide co transport system

6

sodium independently facilitated transport system

glucose transporters GLUT
moves down the concentration gradient

7

sodium monosaccharide co transport system

ATP dependent
transports glucose AGAINST concentration gradient
epithelial cells of intestine, renal tubules and choroid plexus

8

What are two glucose transport proteins

GLUT 2
GLUT 4

9

glucose galactose and fructose
dietary glucose- out of the intestine (into the blood)
into the liver, kidney, pancreas B-cells
insulin independent

GLUT 2

10

glucose into muscle and adipose tissue
stimulated by insulin
stimulated by low energy charge (AMPkinase)
facilitated diffusion

GLUT 4

11

what are glucose transport statistics

in the absense of insulin only 5% of the total transporter pool is found on the cell surface
exercise or insulin result in a 10fold increase in glucose uptake in skeletal muscle
about 90% of insulin stimulated glucose uptake occurs in skeletal muslce
adipose tissue only accounts for 10% of insulin stimulated glucose uptake

12

what does exercise increase the number of

increases the number of GLUT 4 proteins in skeletal muscle

13

what does exercise stimulate the accumulation of

GLUT 4 in the cell membrane for 1-2 hours after exercise

14

what happens when adding a phosphate to glucose do

the glucose concentration in muscle remains low and glucose keeps coming

15

where is glucose

in the blood

16

what happens when muscle energy is low

glucose 6 phosphate runs through glycolysis prep step and krebs to make ATP

17

what happens when glycogen is low

glucose 6 phosphate is converted to glycogen

18

eating carbs does what

elevates blood glucose

19

when having a elevated blood glucose what happens

elevated insulin is caused

20

what happens with a elevated insulin

fat and muscle glucose transport

21

is the muscle full of glycogen after fat and muscle glucose transport

NO glucose is stored as glycogen

22

is the muscle full of glycogen after fat and muscle glucose transport

YES glucose goes to the liver

23

how does glucose enter the muscle

via facilitated diffusion

24

what does high energy and plenty of glycogen stores inhibit

PFK

25

when PFK is inhibited what does it cuase glucose 6 phosphate to do

accumulate and inhibit hexokinase

26

what does higher glucose concentration in muscle inhibit

inhibits facilitated diffusion of glucose

27

glucose goes to the liver

glucokinase

28

glucokinase

lower affinity
stimulated by insulin
not inhibited by product

29

glucokinase does what

runs glycolysis

30

glycolysis runs for

energy and raw material

31

glucose goes to the liver ultimately for

fat building

32

glucokinase

lesser affinity for glucose
not inhibited by its product
stimulated by insulin
stimulated by fructose

33

what does a increase of glucose satisfy

satisfies the low affinity of glucokinase

34

what is the liver a primary site for

for fructose metabolism

35

what does the liver express

frutokinase and triokinase

36

what does fructose stimulate

stimulates glucokinase

37

what is the liver a primary site for

fructose disposal

38

what are the enzymes essential for fructose metabolism and are highly expressed in the liver

fructokinase
triokinase
limited expression in muscle and adipose tissue

39

where is the fructose 1 phosphate pathway

in the liver

40

what is the entry point into glycolysis

glyceraldehyde 3 phosphate

41

what does a low dose of fructose cause

causes a 3fold increase in net liver glycogen synthesis

42

what do smaller amounts of fructose cause

causes the release of glucokinase from a regulatory protein

43

what does not inhibit glucose 6P

glucokinase

44

acetyl CoA to

FAT

45

where does fructose enter at

DHAP G3P

46

what does F6P normally binds to the regulatory protein and what is inhibited

glucokinase

47

F1P binds to the regulatory protein and GK is

set free and activated

48

fructose and fat the liver preferentially takes

in fructose

49

the liver has more what

fructokinase and triokinase enzymes

50

what does fructose stimulate

GK

51

what does fructose and fat produce

more acetyl CoA and ATP
building blocks and energy for building fatty acids

52

excess carbs and protein in the diet do what

synthesize FA
store as TAG

53

where is the pathway primarily

LIVER
lactating mammary glands
adipose tissue

54

what is the FA synthesis location

cytosol Beta oxidation

55

Building fat

Eating carbs raise blood glucose
insulin is secreted
glucose enters the cells

56

energy requiring

ATP

57

reduced conenzyme

nicotinamide adenine dinucleotide P (NADPH)

58

acetyl CoA supplies

carbons for the FA chain
glycolysis>pyruvate>acetly CoA
AA catabolism

59

Acetyl CoA needs to get to the matrix to the cytosol is a

problem

60

high sugar intake increases what

ATP production

61

what can the acetyl portion of acetyl CoA can be transported as

citrate into the cytosol

62

why do we need high energy

to build fat

63

citrate is where

in the inner mitochondrial membrane

64

citrate to acetyl CoA by

ATP added to ADP+Pi
citrate lyase
CoA added

65

carboxylation of acetyl CoA

acetyl CoA to malonyl CoA y acetyl CoA carboxylase coenzyme biotin

66

malonyl CoA inhibits what

CPT I and fat burning

67

what does the reaction of acetyl CoA and Malonyl CoA also require

CO2
ATP

68

synthesis of malonyl CoA

acetyl CoA to Malonyl CoA by acetyl CoA carboxylase conenzyme biotin

69

what is the rate limiting and regulatory step of FA synthesis

acetyl CoA carboxylase ACC

70

Short term regulation of ACC inactive is a what

a protomer=subunit
polymerization= combining subunits

71

what is short term regulation of ACC activated by

citrate

72

what is short term regulation inactivated by

long chain fatty acyl CoA
end product=depolymerization

73

acetyl CoA carboxylase regulation is stimulated by

citrate
insulin

74

acetyl CoA carboxylase regulation is inhibited by

malonyl CoA
palmitate-end product
epineprine
glucagon

75

metformin and type 2 diabetes

inhibtion of ACC
activates AMPK
inhibits ACC and fatty acid synthase
lowers blood glucose

76

the reaction all part of fatty acid synthase the next four steps

condensation
reduction
dehydration
reduction

77

condensation is Acetyl ACP and Malonyl ACP to?

Acetoacetyl ACP by beta ketoacyl ACP synthase

78

REduction Acetoacetyl ACP to D 3 hydroxybutyryl ACP by

beta ketoacyl ACP reductase

79

synthesis

cytosol
acyl carrier protein
adding 2 carbon units
malonyl ACP
NADPH
consuming ATP

80

degradtion

Mitochondria
Coenzyme A
donating 2 carbons units
acetyl CoA
NADH
FADH2
Making ATP

81

conditions that stimulate

high energy charge
increased acetyl CoA
increased NADH and FADH2
increased citrate
increased sugar (glucose fructose)
insulin

82

key enzymes

citrate lyase
acetyl CoA carboxylase
fatty acid syntase CRDR

83

TAG synthesis in the what

mitochondria

84

elongation is accomplished through

elongases and requires NADPH

85

desaturation is accomplished through

desaturates by adding double bonds

86

what are separate enzymatic processes

mitochondria
smooth ER

87

what can humans not create

double bonds beyond the 9-10th carbon

88

NADPH where does it come from

pentose phosphate pathway
malate-pyruvate in cytosol

89

NADPH source of electrons in?

synthesis

90

Fatty acids are what kind of molecules

highly reduced
remember reduction is gain of hydrogen and electrons

91

dehydraton D3 hydroxybutryrl ACP to Crotonyl ACP

by beta hydroxyacyl ACP dehydratase remove H2O

92

reduction 2 by Crotonyl ACP to Butyryl ACP by

Enoyl ACP reductase

93

Palmitate (16:0) when does this process stop

when we have 16 carbon palmiate

94

fatty acid synthesis

reduction
dehydration
reduction

95

fatty acid synthase

CRDR
Condenses-adds molonyl CoA
Reduces- with NADPH
Dehydratase
Reduces- with NADPH

96

release the fatty acid

palmitoyl thioesterase
last step of FAS
cleaves thioester bond and releases saturates palmitate

97

Update:
Butyryl
last 3 carbons are?
still attached to?
Transfer the butyryl chain to the what site?
add another?
when does growth stop

(4 carbons)
hydrogen saturated
ACP
holding site (cysteine)
add malonyl CoA and repeat
at 16 carbons of palmitate

98

long term regulation ACC
high calorie/high carb diet

increase ACC synthesis which increase FA synthesis

99

long term regulation ACC
low calorie/ high fat diet

decrease ACC synthesis which decreases FA synthesis

100

long term regulation ACC
upregulated by insulin

increased response/increased receptors
increase ACC synthesis which increase FA synthesis

101

multi enzyme complex is

FA synthesis
one portion of the molecule is ACP

102

one portion of the molecule is ACP

acyl carrier protein ACP
similar to coenzyme A
terminal thiol group at the end of an arm

103

short term regulation of ACC
reversible phosphorylation

AMP- activated protein kinase AMPK- phosphorylates and inactivates ACC

104

short term regulation of ACC
reversible phosphorylation

can be activated by cAMP dependent PKA
epinephrine and glucagon increase cAMP which phosphorylates and inactivates ACC
insulin dephosphorylates and activates ACC