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Flashcards in Metabolism High Yield Deck (178):
1

Where does beta oxidation occur?

mitochondira

2

Where does glycolysis occur?

cytoplasm

3

Where does HMP shunt occur?

cytoplasm

4

Where does acetyl-CoA production occur?

Mitochondria

5

Where does Heme synthesis occur?

Both mitochondria and cytoplasm

6

Where does urea cycle occur?

mitochondria and cytoplasm

7

Where does TCA cycle occur?

Mitcochondria

8

What type of enzyme adds inorganic phosphate onto substrate with NO use of ATP?

Phosphorylase

9

What type of enzyme calalyzes oxidation reduction reactions?

dehydrogenase

10

What type of enzyme transfers CO2 groups with the help of biotin?

Carboxylase

11

What enzyme relocates a functional group within a molecule?

Mutase

12

What is the rate determining enzyme of glycolysis?

PFK1

13

How does F26BP alter activity of glycolysis?

increased activity of PFK1

14

How does citrate alter the activity of glycolysis?

increased activity of citrate

15

What is the rate determining enzyme of gluconeogenesis?

F16BPase

16

What upregulates F16BPase? What downregulates it?/

Upregulate? ATP and acetyl coA

Downregulate- AMP, F26BP

17

What is the rate determining enzyme of TCA cycle?

Isocitrate dehydrogenase

18

What inhibits isocitrate dehydrogenase?

NADH and ATP

19

What is the rate determining enzyme of glycogenesis?

glycogen synthase

20

What is the rate determining enzyme of glycogenolysis?

glycogen phosphorylase

21

What is the rate determining enzyme of HMP shunt?

G6PD

22

What enhances activity of G6PD?

NADP+

23

What decreases activity of G6PD?

NADPH

24

What is the rate determining enzyme of de novo pyrimidine synthesis?

Carbamoyl phosphate synthetase II

25

What is the rate determining enzyme of de novo purine synthesis?

PRPP aminotransferase

26

What downregulates PRPP aminotransferase activity?

AMP IMP, GMP

27

What is the rate determining enzyme of urea cycle?

carbamoyl phosphate synthetase I

28

What is the rate determining enzyme of fatty acid synthesis?

acetyl coA carboxylase

29

What is the rate determining enzyme of fatty acid oxidation?

Carnitine acyltransferase I

30

What downregulates the activity of carnitine aceyltransferase I?

malonyl- CoA

31

What is the rate determining enzyme of ketogenesis?

HMG- CoA synthase

32

What is the rate determining enzyme of cholesterol synthesis?

HMG- CoA reductase

33

What type of processes is NAD+ used in?

CATABOLIC

34

What type of processes is NADPH used in?

Anabolic processes

35

What pathway produces NADPH?

HMP shunt

36

Where is glukokinase found?

LIVER

37

Where is hexokinase found?

most tissues except the liver and beta pancreatic cells

38

Which has a lower Km... hexokinase or glucokinase?

Hexokinase

39

Which has a higher Vmax...hexokinase or glucokinase?

Glucokinase

40

Which is inducable via insulin...hexokinase or glucokinase?

glucokinase

41

Which is inhibited by G6P...hexokinase or glucokinase?

Hexokinase

42

Which steps of glycolysis produces ATP?

Phosphogylcerte kinase

Pyruvate kinase

43

What inhibits pyruvate kinase?

Alanine and ATP

44

What enzyme is active in the fasting state...FBPase2 or PFK-2?

FBPase2--> converts F26BP back to F6P

45

What enzyme is active in the fed state... FBPase2 or PFK-2?

PFK-2--> converts F6P to F26BP

46

What are the 5 cofactors needed for pyruvate dehydrogenase complex?

B1, B2 B3, B5, Lipoic acid

47

What inhibits lipoic acid?

Arsenic

48

What is the treatment for pyruvate dehydrogenase complex deficiency?

increase intake of ketogenic nutrients (high fat or increased lysine and leucine)

49

What are the symptoms of pyruvate dehydrogenase complex deficiency?

Lactic acidosis, neuro defects and increased serum alanine

50

What 4 molecules does pyruvate lead to?

1- Alanine
2- Oxaloacetate
3- Acyl- CoA
4- Lactate

51

How many molecules of NADH, FADH2, CO2 and GTP produces per acetyl CoA?

NADH- 3
FADH2- 1
CO2- 2
GTP- 1

52

Order of molecules in the TCA cycle?

Citrate
Isocitrate
alpha- Ketogluteate
Succinyl- CoA
Succinate
Fumarate
Malate
Oxaloacetate

53

What complex in the ETC does FAD2 transfter electrons to?

Complex II (lower energy than NADH transfer (complex I)

54

What does rotenone block?

complex I

55

What does cyanide block?

Complex IV

56

What does antimycin A block?

Complex III

57

What does CO block?

complex IV

58

What does oligomycin blocl?

complex V

59

Name 2 uncoupling agents?

2,4- dinitrophenol
Aspirin

60

Name the enzyme:

Pyruvate--> OAA

Pyruvate carboxylase

61

Name the enzyme:

OAA--> PEP

Phosphoenolpyruvvate carboxykinase

62

Name the enzyme:

F16BP--> F6P

F16BPase

63

What gluconeogenesis enzyme do muscles lack?

G6Pase

64

Deficiency in enzymes of gluconeogenesis results in...

hypoglycemia

65

Does HMP shunt produce ATP?

NO!!!

66

Which phase of the HMP shunt produces NADPH?

Oxidtive/ irreversible

67

Aside from producing NADPH, what are the other benefit if the HMP shunt?

Produces glycolytic intermediates and ribose for nucleotide synthesis

68

What enzyme is defieicny in essential fructosuria?

Fructokinase

AR

69

What enzyme is deficienct in fructose intolerance?

Aldolase B

AR

70

What accumulates in fructose intolerance?

F1P

this leads to decrease in phosphate (inhibition of glycogenolysis and gluconeogenesis)

71

What is the treatment for fructose intolerance?

Decrease intake fructose and sucrose

72

What enzyme is deficient in galactose deficiency?

Galactokinase (cannot convert galactose to Galactose 1 Phosphate)

73

What molecule increases in galactokinase deficiency?

Galactitol--> leads to infantile cataracts

74

What enzyme is deficient in classic galactosemia?

Galactose 1 phosphate uridyltransferase

75

What is the treatment for classic galactosemia?

exclude galactose and lactose from diet

76

What is sorbitol metabolized to?

Fructose

77

What enzyme produces sorbitol from glucose?

Aldolase reductase

78

What results from increased sorbitol wthin cells?

Osmotic damage (cataracts, retinopathy, peripheral neuropathy)

79

What is lactose metabolized into?

Glucose + galactose

80

Name the essential gluconeogenic amino acids?

Methionine
Valine
Histidine

81

What are the ketogenic essential amino acids?

Leucine
Lysine

82

What are the essential amino acids that are both ketogenic and glucogenic?

Isoleucine
Phenylalanine
Threonine
Tryptophan

83

Which amino acids are negatively charged at body pH?

Aspartic acid
Glutamic acid

84

Which amino acids are positively charged at the body pH?

Arginine
Lysine
Histidine

85

In the transport of ammonia...amino acids transfer their NH3 to what compound?

Glutamate which then transfers it to alanine

86

What is the cahill cycle?

Alaine (muscle)--> alanine (liver)--> pyruvate--> glucose (liver)--> glucose (muscle)--> pyruvate--> alanine (muscle)

87

What is the cori cycle?

Lactate (muscle--> lactate (liver)--> pyruvate--> glucose (liver)--> glucose (muscle)--> pyruvate --> lactate (muscle)

88

What is the most common deficiency of the urea cycle?

Ornithine transcarbamylase

89

NAG synthase deficiency affects which enzyme in the urea cycle?

Carbamoyl phosphate synthas I

90

Where are the enzymes carbamoyl phosphate synthase and ornithine transcarbamylase located?

Mitochondria

91

What amino acid is the backbone of urea?

Aspartate

92

What is the treatment for hyperammonemia?

Lactulose (ascidify the GI and trap NH4 for excretion

93

Tyrosine is a derivative of which amino acid?

phenylalanine

94

Niacin is a derivative of which amino acid?

Tryptophan

95

Serotonin is a derivative in which amino acid?

Tryptophan

96

Prophyrin and heme is a derivative of which amino acid?

Glycine

97

Glutathione is a derivative of which amino acids?

glutamate

98

Urea is a derivative of which amino acid?

arginine

99

NO is a derivative of which aminoa cid?

argining

100

NE/ DA/ Epi are derivatives of which amino acids?

Phenylalanine

101

Cofactor for dopamine--> NE?

vit C

102

Cofactor for NE--> Epi?

SAM

103

What phenylalanine derivative is melatin made from? What enzyme is responsible?

Made from DOPA

Tryosinase!

104

What is deficient in malignant PKU?

tetrahydrobiopterin cofactor

105

"musty body odor"

PKU

106

What enzyme is deficient in maple syrup urine disease?

alpha ketoacid dehydrogenase

107

"burnt sugar smelling urine"

Maple syrup urine disease

108

What amino acids are to be avoided in maple syrup urine disease?

isoleucine
Leucine
Valine
(branched amino acids)

109

"black urine when exposed to air"

Alkaptonuria

110

What is deficient in alkaptonuria?

Homogentisate oxidase

111

What pathway is defective in alkaptonura?

Tyrosine--> fumarate

112

What are the symptoms of homocystinuria?

1- intellectual disability
2- marfanoid habitus
3- lens sublixation
4- atherosclerosis

113

What amino acids cannot be reabsorbed in the PCT in cystinuria?

COLA

Cystine
Onithine
Lysine
Arginine

114

What type of receptor is the insulin receptor?

tyrosine kinase

115

What type of receptor is glucagon receptor?

increased cAMP--> increased PKA--> increased glycogen phosphoryalase kinase

116

What organ maintains blood sugar at appropriate levels?

Hepatocytes

117

What enzyme breaks alpha 1,4 linkages?

glycogen phosphorylase

118

What are the two debranching enzyme?

4alpha D glucanotransferase

alpha-1,6- glucosidase

119

Is glycogen phosphorylase active when it is dephosphorylated or phosphorylated?

Phosphorylated

120

What enzyme deficiency leads to severe fasting hypoglycemia, increased glycogen in liver, increased blood lactate, increased triglycerides, increased uric acid and hepatomegaly?

Glucose 6 phosphatase

(von gierke disease)

121

What enzyme deficeicny leads to cardiomegaly, hypertrophic cardiomyopathy, exercise intolerance, systemic findings leading to early death?

Lysosomal alpha 1,4 glucosidase (acid maltase)

Pompe disease (type II)

122

What enzyme deficiency leads to is a milder form of type I glycogen storage disease with normal blood lactate levels?

Debranching enzyme (alpha 1,6 glucosidase

Cori Disease (type III)

123

What enzyme deficiency leads to increased glycogen storave in muscles but muscles cannot break it down leading to painful cramps, red urine after strenuous exercise?

Skeletal muscle glycogen phosphorylase (myophosphorylase)

McArdle disease (Type V)

124

How is McArdle disease treated?

B6

125

Deficient enzyme in fabry disease?

alpha- galactosidase A

126

Deficient enzyme in gaucher disease?

Glucocerebrosidase

127

Deficient enzyme in Niemann pick disease?

Shingomyelinase

128

Deficient enzyme in Tay sachs disease?

Heosaminidase A

129

Deficient enzyme in Krabbe disease?

Galactoerebrosidase

130

What enzyme is deficiient in Metachromatic leukodystrophy?

Arylsulfatase A

131

Deficient enzyme in Hurler syndroe?

alpha- L idurinidase

132

What is the deficient enzyme in Hunter syndrome?

Iduronate sulfatase

133

Name the lysosomal storage disease:

progressive neurodegeneration, foam cells, "cherry red" macula, hepatosplenomegaly

Neiman Pick

134

What builds up in nieman pick?

Sphingomyelin

135

Name the lysosomal storage disease:

central and peripheral demyelination with ataxia and dementia

Metachromatic leukodystrophy

136

What builds up in metachromatic leukodystrophy?

cerebroside sulfate

137

Name the lysosomal storage disease:

peripheral neuropathy of hands/ feet, angiokeratomas, CV and renal disease

Fabry disease

138

What builds up in fabry disease?

ceramide trihexoside

139

Name the lysosomal storage disease:

progressive neurodegeneration, delayed development, cherry red macula, lysosomes with onion skin

Tay sachs disease

140

What builds up in Tay sachs?

GM2 ganglioside

141

Name the lysosomal storage disease:

hepatosplenimegaly, pancytopenia, osteoporiss, necrosis of femus, lipid laden macrophages"

gaucher disease

142

What builds up in gaucher disease?

glucocerebroside

143

Name the lysosomal storage disease:

"peripheral neuropathy, developmental delay, optic atrophy, globoid cells

Krabbe disease

144

What builds up in krabbe disease?

Galactocerbroside

145

Name the lysosomal storage disease:

mild developmental delay, mild airway obstruction, mild hepatosplenomegaly, agressive behavior

hunter syndrome

146

Name the lysosomal storage disease:

developpmental delay, gargoylism, airway obstruction, corneal clouding, hepatosplenomegaly

Hurler syndrome

147

Inherited defect in transport of LCFAs in the mitochondria?

Systemic primary carnitine deficiency

148

Fatty acid synthesis requires the transport of _____ from the mitochondria to the cytosol.

Citrate

149

"inability to breakdown fatty acids into acetyl coA leading to accummulation of 8- 10 carbon fatty acyl in the blood"

Medium chain acyl CoA dehydrogenase deficiency

150

What leads to the production of ketone bodies?

Excess acetyl- CoA (glucose and FFA are shunted to ketone formation)

151

What maintains blood glucose levels in fasting states between meals?

hepatic glycogenolysis (major)

152

What maintains blood glucose levels during starvation between 1-3 days?

Hepatic glycogenolysis, adipose release of FFA, muscle and liver, hepatic gluconeogenesis from peripheral lactate and alanine

153

How long does it take for glycogen to be depleted?

1 day

154

What maintains blood glucose levels during starvation after day 3?

adipose stores (ketone bodies from acyl coA)

then after adipose stores are depleted protein degredation accelerates

155

What induces the enzyme HMG- CoA reductase?

insulin

156

What esterifies plasma cholesterol?

LCAT

157

What cells release VLDL?

Hepatocytes

158

What converts chylomiccrons to chylomicron remnants?

LPL

159

What converts VLDL--> IDL?

LPL

160

What converts IDL--> LDL?

Hepatic TG lipase

161

What cells release HDL?

Liver and intestine

162

What enzyme makes nascent HCL mature?

LCAT

163

What is the function of Mature HDL?

Transfer of cholesterol esers to VLDL, IDL, and LDL via CETP (cholesterol ester transfer protein)

164

What is the function of ApoE?

mediates remnant uptake

165

What molecules have ApoE?

Chylomicron
Chylomicron remnant
VLDL
IDL
HDL

166

What is the function of Apo A-I?

Activates LCAT

167

What molecules have Apo A-I?

Chylomicron
HCL

168

What is the function of Apo C-II?

LPL cofactor

169

What molecules have Apo C-II?

Chylomicron
VLDL

HDL

170

What is the function of Apo B-48?

Mediates chylomicron secretion

171

What molecules have Apo B-48?

Chylomicron
Chylomicron remnant

172

What is the function of Apo B-100?

Binds LDL receptor

173

What molecules have Apo B-100?

VLDL
IDL
LDL

174

Which molecule acts as a reserviour of Apo E and C-II?

HDL

175

What secretes HDL?

liver and intestine

176

Which familiar hyperlipidemia has absent LPL or altered Apo C-II?

Type I

177

Which familiar hyperlipidemia has absent or defective LDL receptor?

Type II

178

Which familial hyperlipidemia has hepatic overproduction of VLDL?

Type IV

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