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Flashcards in Exam 2 Deck (104)
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1

What extracellular enzyme hydrolyzes TAG's?

lipoprotein lipase (LPL)

2

What is LPL produced by?

fat and muscle cells

3

Where does hydrolization of TAG occur?

capillary beds

4

Exercise can result in an increase in what enzyme?

skeletal muscle LPL

5

What is the most common storage site for TAG?

adipose tissue

6

FA synthesis is stimulated by what?

insulin

7

What does insulin strongly inhibit that hydrolyzes stored TAG?

HSL

8

During fasting insulin is ______ and glucagon is _______

decreased, increased

9

What gets lipids into the target cell?

LPL

10

What lipase converts TAG to DAG?

ATGL

11

What lipase converts DAG to MAG?

HSL

12

What lipase converts MAG to FFA?

MGL

13

Intracellular lipase is stimulated by?

Hormones (epinephrine, glucagon, adrenocorticotropic)

14

Once a hormone attaches to the Beta-1 receptor on a TAG, what phosphorylates TAG to the active form?

cAMP and adenyl cyclase (2nd messengers)

15

What would PKA stimulate when associate with a TAG?

lipolysis (fat burning)

16

Besides lipolysis, what does PKA stimulate in catabolism of TAG?

HSL

17

If HSL is inhibited, what other lipase is also inhibited?

ATGL

18

What enzyme converts G-3-P to DHAP

G-3-P dehydrogenase

19

Where in the cell does beta oxidation occur?

mitochondrial matrix

20

When the FA first enters the cell, what is activated by to form Acyl-CoA?

Acyl-CoA synthetase

21

What is the location of a FA activated to Acyl-CoA?

outer mitochondrial matrix

22

What is considered the rate limiting step of beta oxidation?

CPT

23

What inhibits CPT?

Malonyl-CoA

24

What is the main enzyme of CPT?

acyl-carnitine translocase

25

What 2 additional enzymes are required for unsaturated FA degradation?

reductase, isomerase

26

Isomerase will break down _____ numbered double bonds

odd

27

Reductase AND isomerase will break down _____ numbered bonds

even

28

What cofactor couples with reductase in unsaturated FA degradation?

NADPH

29

In unsaturated FA degradation, isomerase will convert what enzyme?

trans-Enoyl CoA

30

What is the final product of unsaturated FA degradation?

propionyl CoA

31

What does propionyl CoA get converted to?

succinyl CoA

32

What is the location of ketogenesis?

mitochondrial matrix of the LIVER

33

What is considered the rate limiting step of ketogenesis?

HMG CoA synthase

34

What would stimulate mitochondrial HMG CoA synthase?

prolonged fasting, no/low carbs

35

Cytosolic HMG CoA synthase is used in what pathway?

cholesterol synthesis

36

No carbs, low ATP, and in the liver would stimulate what pathway?

ketogenesis

37

Besides low carbs/starvation, what would create a high concentrations of ketones in the system?

accelerated Beta-oxidation and uncontrolled Type 1 diabetes

38

In ketogenesis, glucagon stimulates what process?

fat burning

39

In ketogenesis, glucagon inhibits what process?

liver glycolysis

40

In ketogenesis, Acetyl CoA inhibits enzyme?

pyruvate dehydrogenase

41

Functional ketone bodies are converted into what to be used to make energy?

acetyl CoA

42

What are the primary sites of glycogen storage?

liver and skeletal muscle

43

Where in the cell is glycogen stored?

cytosol

44

What enzymes breaks alpha(1-4) bonds?

glycogen phosphorylase

45

What is the coenzyme with glycogen phosphorylase?

pyridoxal phosphate

46

What is the product of glycogen phosphorylase breaking the alpha(1-4) bond?

glucose-1-phosphate

47

What enzyme converts glucose -1-phosphate to glucose-6-phosphate?

phosphoglucomutase

48

What enzyme removes outer 3 glucose molecules on glycogen?

glucosyl 4:4 transferase

49

What enzyme removes the last glucose of the branch?

amylo-alpha-1,6-glucosidase

50

What is the key regulatory enzyme of glycogenolysis?

glycogen phosphorylase

51

What hormones are involved in the regulation of glycogen breakdown?

glucagon, epinephrine and norepinephrine

52

What are the allosteric regulators of glycogenolysis?

AMP and calcium

53

On what tissue would glucagon have an effect?

the liver

54

On what tissues would epinephrine and norepinephrine have an effect?

muscle and liver

55

What is adenylyl cyclase activated by in glycogen breakdown?

glucagon, epinephrine and norepinephrine

56

What enzyme is stimulated by the presence of cAMP?

PKA/AMPK

57

In general, what does AMPK inhibit?

synthesis pathways

58

In general, what does AMPK stimulate?

breakdown pathways

59

What would activate glycogen phosphorylase?

AMP

60

What is a subunit of glycogen phosphorylase kinase complex?

calmodulin

61

What are the final products of AA catabolism when creating an alpha-keto acid?

ATP, Glucose, FA

62

What is the main site for AA catabolism?

liver

63

Where are branched chain AA more often catabolized?

skeletal muscle

64

What are the AA that skeletal muscle can oxidize?

LIV (branched) GAA (glutamate, aspartate, asparaine)

65

What coenzyme is required for transamination?

pyridoxal phosphate

66

What is the enzyme used to deaminate glutamate?

glutamate dehydrogenase

67

What cofactor is coupled with glutamate dehydrogenase?

NAD+

68

What is the a-ketoacid of alanine?

pyruvate

69

What is the a-ketoacid of aspartate?

oxaloacetate

70

What is the a-ketoacid of glutamine and glutamate?

a-ketoglutarate

71

What enzyme is used to stick an extra amino group on glutamate?

glutamate synthetase

72

What enzyme in the muscle turns glutamate into glutamine by adding a nitrogen/ammonia?

glutamine synthase

73

In the muscle, what hydrolyzes glutamine back to glutamate?

glutaminase

74

In skeletal muscle, what makes alanine from pyruvate?

ALT or glutamate-pyruvate transaminase (GPT)

75

What enzyme transfers an amino group from glutamate to oxaloacetate to make aspartate?

AST or glutamate-oxaloacetate transaminase (GOT)

76

What does the first NH3 on urea come from?

glutamate dehydrogenase (GDH)

77

Where does the second NH3 on urea come from?

aspartate aminotransferase (AST)

78

What enzyme would create carbamoyl phosphate from Co2, NH3, and 2 ATP?

carbamoyl phosphatase

79

Where in the cell is carbamoyl phosphatase active?

mitochondrial matrix

80

What 2 places in the cell does the urea cycle take place?

cytosol and mitochondrial matrix

81

What can be considered the prep step of the urea cycle?

carbamoyl phosphatase

82

What enzyme cleaves off 2 amino groups to create urea?

arginase

83

A-ketoglutarate entering krebs cycle can be called what process?

anaplerosis

84

Glutamate concentrations in the plasma during exercise tend to?

decrease

85

Alanine concentrations in the plasma during exercise tend to?

increase

86

What is over 90% of muscle amino acid uptake after a meal?

LIV and glutamate

87

What amino acids are released in amounts MORE than they are taken in?

glutamine and alanine (transporters)

88

What amino acids are released in LESS amounts than they are taken in?

LIV GAA

89

What energy charge stimulates oxidation of amino acids?

low energy

90

What enzyme does high energy and plenty of glycogen storage inhibit?

PFK (glycolysis)

91

What enzyme does glucose-6-phosphate accumulation inhibit?

hexokinase

92

What stimulates glucokinase?

insulin and fructose

93

After going through the fructose-1-phosphate pathway, how will fructose enter glycolysis?

as G-3-P

94

Where in the cell does FA synthesis occur?

cytosol

95

What is the main coenzyme of FA synthesis?

NADPH

96

What enzyme combines acetyl-CoA and oxaloacetate to make citrate?

citrate synthase

97

What enzyme creates OAA and Acetly-CoA from cytosolic citrate?

citrate lyase

98

What enzyme creates Malonyl CoA from Acetyl CoA?

Acetyl CoA Carboxylase (ACC)

99

What is the rate limiting step of FA synthesis?

Acetyl CoA Carboxylase (ACC)

100

What is the final step of FA synthesis?

Palmitate

101

Which 2 steps of FA synthesis will use NADPH?

the reduction steps

102

What enzyme will release Palmitate from FA synthesis?

palmitoyl thioesterase

103

What coenzyme is required for elongases?

NADPH

104

What enzyme adds double bonds to Palmitate?

desaturases