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Flashcards in gluconeogensis Deck (103):
1

gluconeogensis occurs when blood glucose is low

starvation
not eating carbs
exercise

2

what hormone stimulates gluconeogensis

glucagon

3

what hormone inhibits gluconeogensis

insulin

4

what is used to make glucose

primarily AA
lactic acid
alanine

5

what happens prior to gluconeogensis

glycogen degradation

6

what are the main entry points to gluconeogensis

pyruvate
oxaloacetate
DHAP

7

what are the main non carb precursors

lactic acid
a keto acids from metabolism AA
glycerol

8

gluconeogensis pathway

pyruvate to glucose

9

what requires glucose

brain
red blood cells
testes
medulla of kidney
cornea of eye
muscle (during high intensity exercise)

10

what requires the most BMR

the BRAIN
liver kidney and heart use the 60-700% of REE

11

glucose vs fatty acid oxidation in the brain

high O2 demand FA oxidation
superoxide
FA oxidation slow the glycolysis
lactate shuttle

12

where is the primary location of gluconeogensis

liver 90%
renal cortex
small intestine

13

how do you make gluconeogensis favorable

alternative enzymes (cytosol and mitochondria)
coupled RXNS
ATP

14

what are glycolysis irreversible reactions

hexokinase
phosphofructokinase
pyruvate kinase

15

how many reactions are reversible in glycolysis

7

16

First obstacle in glycolysis

phosphoenolpyruvate to pyruvate
By: pyruvate kinase (ADP to ATP)

17

happening in the mitochondria; Pyruvate to oxaloacetate by?

Pyruvate carboxylase
coenzyme: Biotin
(take away ATP)

18

where is pyruvate carboxylase present

in mitochondria of liver and kidney
also present in muscle but does not synthesize glucose (uses OAA produced as intermediate in krebs)

19

where is pyruvate sent

to mitochondria

20

whats the precursor for pyruvate carboxylase

pyruvate or alanine

21

what is pyruvate converted to

oxaloacetate

22

what is pyruvate carboxylase required enzyme

biotin

23

where does oxaloacetate need to get into

get into the cytosol through the malate shuttle

24

in the mitochondrial matrix; pyruvate is transferred to what and then that is transferred to what

pyruvate to oxaloacetate(pyruvate carboxylase) to malate (malate dehydrogenase)

25

in the cytosol; malate is transferred to what then to what

malate to oxaloacetate (malate dehydrogenase) to phosphoenolpyruvate (PEP carboxylase)

26

when is acetyl CoA produced

during FA oxidation

27

what does acetyl CoA stimulate

pyruvate carboxylase

28

what does elevated Acetyl CoA in the mitochondria signal

a need for more OAA in the cell

29

PEP carboxylase is dependent on what

MG+

30

if lactate was the precursor the reaction happens where

in the mitochondria aand PEP will be transported to the cytosol

31

what are two high energy compounds required to overcome the 1st obstacle

ATP-1st
GTP-2nd

32

what does the malate shuttle do

pyruvate or alanine precursor
provides reducing power in the cytosol for later reactions
NADH

33

what pathway makes glucose

gluconeogensis

34

lactate as a precursor

anerobic glycolysis
erythrocyte glycolysis

35

does lactate need a malate shuttle to go to pyruvate

no; this also happens in the cytosol and yields NADH

36

what is still sent to the mitochondria

pyruvate to make
pyruvate carboxylase
PEP carboxylase occur in mitochondira
PEP then transported to cytosol

37

what is not a substrate for gluconeogensis

leucine

38

what is not a irreversible step of glycolysis

phosphoglyecerate kinase

39

the 2nd obstacle to overcome; Fructose 1-6 bisphosphate to Fructose 6 phosphate by what

fructose 1-6 bisphosphatase and is MG+ dependent

40

the third obstacle to overcome; glucose to glucose 6 phosphate by

glucokinase (ATP to ADP)

41

glucose 6 phosphate to glucose by

glucose 6 phosphatase
MG+ dependent
releases a free P

42

what does not release glucose

muscle because it does not have G6P

43

what can release glucose

the liver because it has G6P

44

enzymes for glycolysis and gluconeogensis:

Glucokinase>G^P
Phosphofructokinase>Fructose 16 Bisphosphatase
Pyruvate kinase> PEP carboxylase or pyruvate carboxylase

45

what is gluconeogensis

it is energetically expensive

46

for each glucose formed from pyruvate there are

6 high energy phosphate groups:
4 ATP
2 GTP
2 NADH

47

what are the gluconeogenic substrates

glyerol- backbone TG
lactic acid- waste product glycolysis
a-ketoacids(more to come)

48

derived from glycogenic AA
pyruvate OAA a ketoglutarate
can enter into the TCA forming OAA
OAA is the direct recursor to PEP

a ketoacids

49

what does glycerol form the backbone for

TG
hydrolysis of TG in adipose
transported in blood to the liver

50

what can glycerol also be converted to

glucose

51

what is not a major source of glucose

glycerol

52

glycerol to glycerol phosphate by:

glycerol kinase

53

glycerol phosphate to DHAP by:

Glycerol phosphate dehydrogenase

54

glycolysis stimulators

glucose
insulin
AMP ADP
NAD+
F 2 6 BP

55

glycolysis inhibitors

ATP
NADH
Glucagon
Pyruvate
Lactate
Alanine
Citrate

56

gluconeogenis stimulators

glucagon
Acetyl CoA
Citrate

57

gluconeogensis inhibitors

glucose
inulin
AMP ADP
F 2 6 BP

58

muscle conditions during exercise

exercise lowers ATP

59

muscle active pathways during exercise

glycogen breakdown
Glut 4 translocation
Glycolysis
TAG breakdown
Beta oxidation
AA oxidation
Krebs

60

liver conditions during exercise

Glucagon
High ATP

61

Liver active pathways during exercise

Glycogen breakdown
Gluconeogensis
Urea cycle

62

What is the lactic acid cycle also called

Cori cycle

63

What is the lactic acid cycle

Exercise: anaerobic glycolysis produces lactate

64

Where is lactate released from

Working muscle
And also RBC

65

Where is lactate transported to

The liver to become glucose

66

Where does the glucose return to

Returns to the muscle

67

Muscle glycogen to

Glucose 6P

68

Glucose 6P to

Krebs or lactate

69

Lactate to where

The liver to turn to pyruvate

70

Pyruvate to what

Glucose then back to the muscle

71

What lowers blood glucose

Exercise

72

What's secreted in response to low blood glucose

Glucagon

73

What's lactate released by

Muscle

74

Where is lactate transported to

The liver

75

What is stimulated by glucagon

GNG (liver)

76

What is lactate to pyruvate enzyme

Lactate dehydrogenase

77

Where is glucose released into

The blood

78

Where does glucose return to

The muscle

79

Lactate to glucose is what

GNG

80

What are most AA classified as

Glucogenic

81

A ketoacids are

Carbon skeletons of AA

82

What's the primary source of glucose from GNG at rest and during fasting

A ketoacids

83

What is sit kited by starvation or low carbs intake

The conversion of AA into glucose

84

What is a AA turned into before it becomes glucose

A ketoacids

85

Where do a ketoacids come from

AA break down

86

What are the essential glucogenic AA

Think MAV H PITT
Methionine
Arginine
Valine
Histidine
Phenylalanine
Isoleucine
Tryptophan
Threonine

87

What happens to a ketoacids depends upon what

Energy charge
Hormones glucagon insulin
Glucose concentration
Tissue liver versus muscle

88

What are amino groups transferred from

Glutamate to pyruvate

89

Where is alanine transported to

The liver

90

What is alanine converted back to

Pyruvate for GNG

91

Where is glucose transported back to

Muscle

92

Alanine is a BLANK and converted to pyruvate which is a BLANK

AA
A ketoacids

93

Insulin inhibits what

GNG

94

Glucagon stimulates what

GNG LIVER

95

Insulin does what

B cells of the pancreas
Lowers blood sugar
Stimulate glucose utilizing pathways

96

Glucagon does what

A cells of the pancreas
Elevated blood sugar
Stimulates pathways that do it need glucose

97

What does F26BP Stimulate

Glycolysis
PFK in the liver

98

What does F26BP inhibit

GNG
F16BP

99

What decreases F26BP

Glucagon

100

Muscle contracts and uses ATP
Low energy charge
Lowers blood glucose

Exercise sequence part 1

101

Low energy charge

Stimulates glycogen breakdown
Stimulate glycolysis (more lactic acid, more alanine)
Stimulate krebs
Stimulate glucose entry into muscle

102

Secrete glucagon

Exercise sequence part 2

103

Secrete glucagon

Stimulate glycogen breakdown in the liver
Stimulates GNG in the liver (uses lactic acid and alanine in the liver)
Inhibits glycogen synthesis in the liver
Slows down glycolysis in the liver