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Flashcards in metabolism A Deck (102)
1

which enzyme is found only in the liver

phosphatase

2

why is phosphatase found only in the liver

glycogen in the liver must provide glucose for the entire body

3

what does phosphatase do

convert glucose-6-phosphate to glucose

4

when glucagon affects a liver cell, a phosphate is attached to both glycogen synthetase and glycogen phosphorylase.
which enzyme is activated?

glycogen phosphorylase

(glucagon is trying to raise blood sugar)

5

what compounds can be converted to glucose in gluconeogenesis

lactic acid

glycerol

some amino acids

6

which cells need insulin for glucose entry

muscle cells

liver

adipose

7

if glycogen synthetase were allosteric, what effect would ATP have on it

active

excess ATP means that there is no need for glycolysis
glucose should be stored as glycogen

8

what happens to MOST of the glucose-6-phosphate in liver versus muscle tissue

1. In muscle it is used for energy, in liver it is converted to glucose to be transported by the blood to other cells

2. they can both be converted to glycogen if not needed

Liver uses fatty acids for most of its energy needs

9

Exothermic reactions

1. oxidation glucose to CO2 H2O
2. succinyl-CoA--> succinic acid & coenzyme A
3.GTP --> GDP & Pi
4. hydrolysis of acetyl-CoA
5. hydrolysis of glucose-6-phosphate to glucose
6. CH3CH2OH to CH3CH=O

10

cannot be converted back to glucose-1-phosphate

fructose-1,6-biphosphate

step # 3 in glycolysis is irreversible

11

the purpose of the cori cycle is

move lactic acid out of the muscle

have the liver provide the muscle with "new" glucose

12

oxidation reactions

are always exothermic

13

oxidation of glucose to CO2 H2O

exothermic

14

glycogen synthesis

endothermic

15

ADP & Pi --> ATP

endothermic

16

Conversion of glucose-1-phosphate to glucose-6-phosphate

endothermic

17

succinyl-CoA --> sussinic acid & coenzyme A

exothermic

18

GTP --> GDP & Pi

exothermic

19

all anabolic reactions

endothermic

20

photosynthesis

endothermic

21

hydrolysis of acetyl CoA

exothermic

22

formation of glucose-6-phosphate from glucose

endothermic

23

hydrolysis of glycogen to glucose

exothermic

24

hydrolysis of glucose-6-phosphate to glucose

exothermic

25

CH3CH2OH to CH3CH=O

exothermic

26

does NOT occur in "fight or flight"

epinephrine crosses cell membrane to stimulate glycogenolysis

epinephrine cannot enter the cell

27

which occurs during "fight or flight"

1. glycogen is converted to glucose-1-phosphate in the muscles
2. epinphrine stimulate the production of cyclic-AMP in muscle cells
3. cAMP causes the glycogen synthetase to be deactivated
4. glycogenolysis is stimulated

28

proteins (polypeptides)

Glucagon
Insulin
Lactic acid dehydrogenase

29

polysaccharides

glycogen

30

can move through a cell membrane

glucose
cortisol

31

can stimulate fatty acid synthesis from acetyl CoA

insulin

32

stimulate the immediate conversion of glycogen to glucose-1-phosphate in the liver

Glucagon

33

stimulate the conversion of certain amino acids to glucose in gluconeogenesis

cortisol

Glucagon

34

Reverse of the other

1. anabolism & catabolism
2. glycogenolysis & glycogenesis
3. photosynthesis & complete oxidation of glucose

35

produces the most ATP in glycolysis

fructose-1,6-biphosphate

there are already 2 phosphates on the molecule

36

produces the least ATP in glycolysis

glucose

37

in anaerobic exercise the pH of the muscle will

decrease

acidosis

38

which processes needs alot of ATP

muscle activity

synthesizing protein from amino acid

active transport

all anabolic reactions

39

reactions can be coupled so

one reaction drives the other

40

hydrolysis of glucose-1-phosphate to glucose give 5 kcal/mole

fructose-6-phosphate to fructose give 3.8

glucose-6-phosphate to glucose 3.8

creatine phosphate to creatine give 10.3

ATP to ADP and Pi gives 7.5 kcal/mol

which reactions would be exothermic or favorable

creatine phosphate & ADP to creatine & ATP

41

get 3.8 from fructose-1-P to fructose need 7.5 for ADP & Pi to ATP

total needed 3.7

42

get 10.3 from creatine-phosphate to creatine need 7.5
ADP & Pi to ATP

total get 2.8

43

get 3.8 from glucose-6-P to glucose need 10.3 for creatine to creatine-phosphate

total need 6.5

44

inhibits glycogenesis in the liver
(hormone)

Glucagon

45

stimulates glycogenolysis in the muscle
(hormone)

Epinephrine

46

stimulates entry of glucose into a muscle cell
(hormone)

insulin

47

inhibits gluconeogenesis
(hormone)

Insulin

48

stimulates entry of glucose into brain cells
(hormone)

none

49

Glycogen to glucose-1-phosphate

(enzyme catalyzes)

Phosphorylase

50

Glucose-1-phosphate to glucose-6-phosphate

(enzyme catalyzes)

mutase

51

GLucose & ATP to glucose-6-phosphate & ADP

(enzyme catalyzes)

kinase

52

Glucose-6-phosphate to glucose

phosphatase

53

if glycolysis is taking place in a red blood cell, where is the starting point

glucose

54

the purpose of converting pyruvic acid to lactic acid is to regenerate

NAD

55

which cannot move through a cell membrane

glycogen
glucose-1-phosphate
protein hormones
epinephrine
polypeptides

56

can move through cell

glucose
CO2
galactose
steroid hormones
fatty acids
glycerol
amino acids

57

glycogen

cannot move through cell

polysaccharide

58

glucose-1-phosphate

cannot move through cell

phosphate prevents moving through membrane

59

protein hormones

cannot move through cell

60

epinephrine

cannot move through cell

61

polypeptides

cannot move through cell

62

true of insulin

inhibits glycogenolysis

stimulates entry of glucose into muscle tissue & liver tissue

63

FALSE of insulin

1. too much insulin will result in hyper glycemia
2. stimulates entry of glucose into brain cells
3. it stimulates gluconeogenesis

64

the cAMP system is used for

mainly protein hormones

65

digestion is mainly a process of

hydrolysis

66

which process is MOST important in the maintenance of a constant blood glucose concentration

synthesis and breakdown of glycogen in the liver

67

TRUE diabetes

1. it will occur when there are not enough insulin receptor sites
2. it will occur when not enough insulin is secreted (released) by the pancreas
3. kidneys will excrete large amounts of water in order to remove excess sugar from the blood

68

FALSE of diabetes

1. occur when not enough insulin is produced by the liver
2. can cause hyperglycemia
3.

69

when a phosphate is added to an enzyme to either activate it or deactivate it

covalent modification

70

what is called the "famine" hormone

famine= glucagon

71

"feast" hormone

feast=insulin

72

where is galactose converted to glucose

liver

73

the breakdown of food molecules into simpler chemical substances that can be absorbed by the body is called

digestion

74

what substance is secreted from the adrenal glands in response to low blood sugar levels, strenuous exercise or stress

epinephrine

adrenaline

75

what type of enzyme is needed to convert pyruvic acid to acetalaldehyde in fermentation

decarboxylase

76

starting with glucose, which steps in glycolysis are using up ATP

#3
#1

77

where does digestion start for proteins

stomach

78

where does digestion start for carbohydrates

mouth

79

where does digestion start for lipids [not metabolism]

small intestines

80

when epinephrine reaches the receptor cell on

muscle cells

81

when empinphrine reaches the receptor cell on muscle cells, it stimulates the process called

glycogenolysis

82

what happens when glucagon affects a liver cell

glucagon turns on adenyl cyclase which stimulates the reaction ATP to cAMP

kinase enzymes are turned on so phosphate can be put on glycogen synthetase and glycogen phosphorylase

83

what are the effects of glucagon
1. glucose is converted to glycogen in the liver
b. glycogenolysis is stimulated in the liver and muscle
c. gluconeogenesis is inhibited
d. none

none

84

conversion of glucose-6-phophate to fructose-6-phosphate needs an isomerase enzyme and ATP for energy

false

no ATP is needed

85

RBCs do not have mitochondria so they must get all their energy from glycolysis

true

86

in a reaction that is energetically unfavorable, the energy of the products is more than the energy of the reactants

true

87

oral anti-diabetic drugs are similar to insulin in their structure

false
they are not proteins
proteins would be digested in the stomach

88

oral anti-diabetic drugs help with only some types of diabetes

they help increase the release of insulin from the pancreas
but no the original amount of insulin produced

89

Glucose 1-phosphate

Mutase
Isomers see

90

Glucose6-phosphate---> liver only

Phosphatase

Glucose--> to blood

91

Glucose 6-phosphate--ATP/ADP--> glucose.

Kinase
ATP-->ADP

Blood

92

Glucose 6-phosphate fructose 6-phosphate

Isomerase

93

Fructose 6-phosphate --ATP ADP--> fructose 1,6-biphosphate

Allosteric
Inhibited by ATP

Kinase

94

NAD
NADH

Dehydrogenase

95

-CO2

Decarboxylase

96

ATP
ADP

Kinase

97

Steps 7+ 10

Substrate level phosphorylation

98

Oxidative pathways

Kreb cycle
Aerobic

99

Muscle..

Anaerobic

100

Yeast

Anaerobic

Fermentation

101

Allosteric

Inhibited ATP

Using up ATP

Putting P on
Against gradient

102

Step 6

Glyceraldehyde 3-phosphate -P. NAD NADH-> 1,3 biphosphoglyceric acid

Coupling
Endothermic
Putting P on