Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

0. Step Ib > Biochem - all pathways > Flashcards

Biochem - all pathways Flashcards

1
Q

Pompe Disease

signs?

enzyme defect?

A

severe cardiomeagly, hepatomeagly, macroglossia, hypotonia, mental retardation, glycogen accumulation in lysosomes

∆ alpha-glucosidase/acid maltase - converts branched glycogen -> glucose in lysosomes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

McArdle Disease

signs?

enzyme defect?

A 
increased muscle glycogen
sx occurs w/ exercise
- weakness + fatigue, little to no rise in blood lactate
- myoglobinuria
- arrhythmias + electrolyte ∆s

∆ glycogen phosphorylase - converts branched glycogen -> limit dextrans

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Cori Disease

signs?

enzyme defect?

A

accumulation of small chain dextrin-like material in cytosol
hypoglycemia
hyperTg
ketoacidosis
hepatomeagly
(basically a milder version of Von-Gierke but with normal lactate levels)

∆ debranching enzyme - converts limit dextrans -> glycogen

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

RA: ∆ alpha-glucosidase/acid maltase

A

Pompe Disease

converts branched glycogen -> glucose in lysosomes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

RA = ∆ glycogen phosphorylase

A

McArdle Disease

converts branched glycogen -> limit dextrans

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

RA = ∆ debranching enzyme

A

Cori disease

converts limit dextrans -> glycogen

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Mild Galactosemia

signs?

enzyme defect?

A

galactosuria
cataracts (due to galacticol accumulation) - failure to tract objets, ø social smile
no hepatomeagly

∆ galactokinase - converts galactose -> galactose-1-P

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Severe Galactosemia

signs?

enzyme defect?

trmt?

A

failure to thrive
intellectual disability
cataracts
hepatomeagly (due to PO4 depletion, therefore no gluconeogenesis, no glycogenolysis)

∆ G1P uridyltransferase - converts galactose-1-P -> glucose-1-P

Trmt: exclude galactose + lactose

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

RA = ∆ galactokinase

A

Mild Galactosemia

converts galactose -> galactose-1-P

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

RA = ∆ G1P uridyltransferase

A

Severe Galactosemia

converts galactose-1-P -> glucose-1-P

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

RA = trmt: exclude galactose + lactose

A

Severe Galactosemia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Cataracts, retinopathy, and peripheral neuropathy in a patient w/ poorly controlled diabetes should make you think of….

A

sorbitol accumulation in schwann cells, retina, and kidneys due to ∆ sorbitol dehydrogenase (converts sorbitol -> fructose)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Von Gierke

signs?

enzyme defect?

trmt?

A

severe fasting hypoglycemia
hepatomeagly (due to increased glycogen in liver)
increased blood lactate (more gets funneled down)

∆ Glucose-6-phosphatase - converts glucose-6-P -> Glucose

trmt: frequent oral glucose + starch; avoid fructose and galactose

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

RA = ∆ sorbitol dehydrogenase

A

sorbitol accumulation sorbitol accumulation in schwann cells, retina, and kidneys

converts sorbitol -> fructose

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

RA = ∆ Glucose-6-phosphatase

A

Von Gierke

converts glucose-6-P -> Glucose

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

RA = trmt: frequent oral glucose + starch; avoid fructose and galactose

A

Von Gierke

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Hemolytic Anemia in PPP

signs?

enzyme defect?

A

hemolytic anemia w/ exposures to oxidative stress (due to øNADPH)

  • sulfa Rx
  • antimalarials
  • infection/free radicals
  • fava beans
  • anti-TB Rx

∆ G6P DH - converts glucose-6-P to 6-phosphogluconate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Essential Fructosuria

signs?

enzyme defect?

A

Fructosemia + fructosuria (reducing agent in urine)

∆ fructokinase - converts fructose -> fructose-1-P

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Fructose Intolerance

signs?

enzyme defect?

A

Fructosuria
decreased glycogenolysis + gluconeogenesis (due to decr. P)
sx that occur after consuming fruit juice/honey:
- hypoglycemia
- jaundice
- cirrhosis
- vomiting

∆ Aldolase B - converts fructose-1-P to glyceraldehyde

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Hemolytic Anemia in Glycolytic Pathway

signs?

enzyme defect?

A

hemolytic anemia (due to ø glycolysis and ø ATP to maintain RBC structure)

∆ pyruvate kinase - converts PEP -> Pyruvate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

RA: ∆ G6P DH

A

Hemolytic anemia due to PPP

converts glucose-6-P to 6-phosphogluconate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

RA: ∆ Fructokinase

A

Essential Fructosuria

converts fructose -> fructose-1-P

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

RA: ∆ Aldolase B

A

Fructose Intolerance

converts fructose-1-P to glyceraldehyde

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

RA: ∆ pyruvate kinase

A

hemolytic anemia in glycolytic pathway

converts PEP -> Pyruvate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

∆ pyruvate carboxylase

A

downregulation of Citric acid cycle/energy producing capacity of the cell

converts Pyruvate -> oxaloacetate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

∆ pyruvate dehydrogenase

signs?

trmt?

A

Lactic acidosis
increase serum alanine
neurological defects

trmt: increase fat, lysine, leucine

converts pyruvate -> Acetyl CoA

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

arsenic blocks these two enzymes

net ATP?

A

pyruvate DH
alpha-ketoglutarate DH

net: 0 ATP

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

Symptoms due to defects in carnitine shuttle

A

hypoketoic
hypoglycemia
hyptonia (weakness)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

∆ Acyl-CoA DH

A

low fasting glucose

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

Maple Syrup Disease

signs?

enzyme defect?

trmt?

A 
CNS defects (retardation)
urine that smells like burnt sugar/maple syrup

∆ alpha-keto acid dehydrogenase - converts branched chain a.a. to propionyl CoA

trmt: decrease isoleucine, leucine, valine, increase thiamine (B1)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

Folic acid deficiency

A

Macrocytic anemia
hypersegmented PMN
Increased homocysteine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

Cobalamin deficiency

A

Macrocytic anemia
hypersegmented PMN
DCML problems
Increased homocysteine + methylmalonyl CoA

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

Homocystinuria

signs?

enzyme defect?

trmt?

A 
downward + inward lens displacement
kyphosis
osteoporosis
stroke, MI
intellectual disability

∆ homocysteine methyltransferase - 2 reactions:
homocystine -> methionine
methylmalonyl CoA -> succinyl CoA

trmt: pyridoxine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

RA: ∆ alpha-keto acid dehydrogenase

A

Maple Syrup Disease

converts branched chain a.a. to propionyl CoA

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

RA: ∆ homocysteine methyltransferase

A

homocystinuria

homocystine -> methionine
methylmalonyl CoA -> succinyl CoA

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

Ornithine transcarbamylase deficiency

signs?

enzyme defect?

trmt?

A

increased orotic acid
hyperammonemia
ø megaloblastic anemia
decreased BUN

trmt: restrict proteins

∆ = Ornithine transcarbamylase (OTC) - converts urea cycle intermediates -> carbomoyl phosphate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

Orotic Aciduria

signs?

enzyme defect?

trmt?

A

needle-shaped orotic acid crystals
ø hyperammonemia
megaloblastic anemia (hypochromic)
hypersegmented nuclei

∆ UMPS (orotidine phosphorribosyl Transferase and Orotidine-5-phosphate decarboxylase) - converts orotic acid -> UMP

trmt: uridine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

Hyperammonemia + increased ornithine

A

∆ N-acetyl glutamate - cofactor of carbamoyl phosphate synthetase (CPSI), which converts NH3 + CO2 -> carbomoyl phosphate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

RA: ∆ Ornithine transcarbamylase (OTC)

A

Ornithine transcarbamylase deficiency

converts urea cycle intermediates -> carbomoyl phosphate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

RA: ∆ orotidine phosphorribosyl transferase

A

Orotic Aciduria - part of UMPS complex with orotidine-5-phosphate decarboxylase

converts orotic acid -> UMP

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

RA: ∆ orotidine-5-phosphate decarboxylase

A

Orotic Aciduria - part of UMPS complex with orotidine phosphorribosyl transferase

converts orotic acid -> UMP

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
42
Q

difference between CPS I and CPS II?

how do you tell if one is deficient over the other?

A

CPS I - converts NH3 + CO2 to carbomyl phosphate; requires N-acetylglutamate

CPS II - converts glutamine + CO2 to carbomyl phosphate

w/ CPSI deficiency, you get increased ornithine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
43
Q

Lesch-Nyhan

signs?

enzyme defect?

trmt?

A

self-mutilating behavior
excess uric acid

trmt: allopurinol, febuxostat

∆ HGPRT - converts guanine/hypoxanthine -> GMP, IMP

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
44
Q

SCID

signs?

enzyme defect?

A

excess ATP
decreased lymphocytes
decreased DNA synthesis

∆ ADA - converts AMP -> guanine/hypoxanthine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
45
Q

RA: ∆ HGPRT

A

Lesch-Nyhan

converts guanine/hypoxanthine -> GMP, IMP

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
46
Q

RA: ∆ ADA

A

SCID

converts AMP -> guanine/hypoxanthine

47
Q

RA: trmt: allopurinol, febuxostat

A

Lesch-Nyhan

48
Q

PKU

signs?

enzyme defect?

trmt?

A 
ø melanin, pale fair skinned
musty body odor
eczema
seizures, intellectual disability
growth retardation
increased phenylketones in urine (phenyl-acetate, -lactate, -pyruvate)
tyrosine becomes an essential a.a.

∆ phenylalanine hydroxylase - converts phenylalanine -> tyrosine

trmt: decrease phenyalanine, increase tyrosine, avoid aspartame

49
Q

Albinism

A

ø melanin, pale fair skinned

∆ tyrosinase - converts DOPA -> melanin

50
Q

Alkaptonuria

signs?

enzyme defect?

A

urine turns dark @ room air
brown connective tissue + sclera
arthralgia

∆ Homogenistic acid oxidase - converts Homogenistic acid -> maleyacetoacetic acid

51
Q

RA: ∆ phenylalanine hydroxylase

A

PKU

52
Q

RA: ∆ tyrosinase

A

Albinism

53
Q

RA: ∆ Homogenistic acid oxidase

A

Alkaptonuria

54
Q

Sideroblastic anemia

A

∆ ALAS or B6 (losses inducible by isoniazid)

no B6 -> peripheral neuropathy, convulsions, irritability

55
Q

lead inhibits these two enzymes

A

ALAD, Ferrochetolase

56
Q

Acute intermittent porphyria

signs?

enzyme defect?

trmt?

A

painful abdomen
port-wine colored urine
polyneuropathy (muscle weakness)
psychological ∆s

trmt: glucose + heme (feeds-back to inhibit ALAS)

∆ Porphobilinogen deaminase - converts porphobilinogen -> Hydroxymethylbilane

57
Q

Porphyria cutanea tarda

signs?

enzyme defect?

A

blistering cutaneous photosensitivity

∆Uroporphyrinogen decarboxylase - converts Uroporphyrinogen III -> Coproporphyrinogen III

58
Q

RA: ∆ porphobilinogen deaminase

A

converts porphobilinogen -> Hydroxymethylbilane

59
Q

RA: ∆Uroporphyrinogen decarboxylase

A

converts Uroporphyrinogen III -> Coproporphyrinogen III

60
Q

RA: trmt: glucose + heme

A

Acute intermittent porphyria

61
Q

Crigler-Najjar Syndrome

signs?

enzyme defect?

trmt?

A

jaundice
kernicterus (bilirubin deposition in brain)
increased unconj. bilirubin.

trmt: plasmapheresis and phototherapy

∆ UDP-glucuronosyltransferase - converts bilirubin -> bilirubin diglucuronide, water soluble

62
Q

Gilbert syndrome

signs?

enzyme defect?

A

symptomatic or mild jaundice
elevated unconj. bilirubin w/o overt hemolysis
bilirubin increases w/ fasting and stress.

low UDP-glucuronosyltransferase - converts bilirubin -> bilirubin diglucuronide, water soluble

63
Q

Dubin- Johnson syndrome

signs?

enzyme defect?

A

Conjugated hyperbilirubinemia
black liver

defective liver excretion-> obstructive jaundice

64
Q

Rotor syndrome

signs?

enzyme defect?

A

mild conjugated hyperbilirubinemia
ø black liver

decreased liver excretion-> obstructive jaundice, milder version of DJ syndrome

65
Q

RA: ∆ UDP-glucuronosyltransferase

A

Crigler-Najjar

converts bilirubin -> bilirubin diglucuronide, water soluble

66
Q

RA: low UDP-glucuronosyltransferase

A

Gilbert syndrome

converts bilirubin -> bilirubin diglucuronide, water soluble

67
Q

RA: defective liver excretion-> obstructive jaundice

A

Dubin Johnson syndrome

68
Q

RA: decreased liver excretion-> obstructive jaundice

A

Rotor syndrome

69
Q

derivative of NO

A

argnine

70
Q

derivatives of urea

A

arginine + aspartate

71
Q

derivatives of heme

A

glycine + succinyl CoA

72
Q

derivatives of creatinine

A

glycine + arginine + SAM

73
Q

derivatives of GABA

A

glutamate

74
Q

derivatives of glutathione

A

glutamate

75
Q

derivatives of pyrimidines

A

glutamate + aspartate

76
Q

derivatives of purines

A

glutamate + aspartate + glycine

77
Q

derivatives of histamine

A

histidine

78
Q

derivatives of dopamine

A

phenylalanine

79
Q

derivatives of melatonin

A

tryptophan

80
Q

derivatives of niacin

A

tryptophan

81
Q

derivatives of thyroxine, melanin

A

tyrosine

82
Q

Net ATP from aerobic respiration in the heart + liver
Net ATP from aerobic respiration in the muscle

Net ATP from anaerobic respiration

Net ATP from arsenic poisioning

A 
32 = heart + liver
30 = muscle

anaerobic = 2

arsenic = 0

83
Q

glucokinase is present in what tissues? hexokinase?

A 
glucokinase = liver, ß cells of pancreas
hexokinase = all other tissues
84
Q

Which gene is associated with maturity-onset diabetes of the young?

A

Glucokinase

85
Q

How do these affect oxidative phosphorylation?

Rotenone, cyanide, antimycin A, CO

A

all inhibit electron transport, resulting in a DECREASED proton gradient and no ATP synthesis

“DRACCO”

86
Q

How does oligomycin affect oxidative phosphorylation?

A

inhibits ATP synthase, resulting in INCREASED proton gradient and no ATP synthesis

87
Q

How does 2,4-DNP, aspirin, and thermogenin affect oxidative phosphorylation?

A

increases permeability of the membrane, resulting in decreased proton gradient and increased O2 consumption

ATP synthesis stops, but e-transport continues, resulting in heat production

88
Q

essential a.a

A

isoleucine, phenylalanine, threonine, tryptophan
lysine, leucine
methionine, histidine, valine

“PITT LYed to LUCy about going to the MET w. HIS ex VALerie

89
Q

a.a. in histones

A

arginine and lysine

90
Q

acidic a.a.

A

glutamic acid
aspartic acid

“GLUe is esp (ASP) acidic”

91
Q

basic a.a.

A

Histidine
Lysine
Arginine

“HIS LYes ARe basic”

92
Q

purpose of Cori cycle?

What drug can inhibit this cycle and what happens?

A

transports lactate to the liver for gluconeogenesis to prevent lactic acidosis in muscles

pathway can be inhibited by METFORMIN, resulting in lactic acidosis in patients with renal failure since the kidneys can’t handle excess lactic acid

93
Q

purpose of alanine cycle?

A

shuttles alanine to the liver to make more glucose and to prevent NH3 buildup in muscles

94
Q

pathophysiology of hepatic encephalopathy?

sx?

trmt?

A

liver dz (cirrhosis) or urea cycle enzyme deficiencies can result in an excess of NH4, which depletes a-KG, leading to an inhibition of TCA

sx: tremor (asterixis), slurring of speech, somnolence, vomiting, cerebral edema, blurring of vision

Trmt: limit protein, Benzoate or phenylbutryate (bind a.a. and lead to its excretion) or Lactulose (acidifies GI to trap NH4 for excretion)

95
Q

∆ N-acetylglutamate

A

required cofactor for CPS I (carbamoyl phosphate synthetase I)

leads to HYPERAMMONEMIA

increased ornithine (compare to a pure CPSI deficiency)

96
Q

serotonin is derived from which a.a.?

A

tryptophan

97
Q

niacin is derived from which a.a.?

A

tryptophan

98
Q

melatonin is derived from which a.a.?

A

tryptophan

99
Q

histamine is derived from which a.a.?

A

histidine

100
Q

heme is derived from which a.a.?

A

glycine

101
Q

porphyrin is derived from which a.a.?

A

glycine

102
Q

GABA is derived from which a.a.?

A

glutamate

103
Q

glutathione is derived from which a.a.?

A

glutamate

104
Q

creatinine is derived from which a.a.?

A

argninine

105
Q

urea is derived from which a.a.?

A

argninine

106
Q

NO is derived from which a.a.?

A

argninine

107
Q

DOPA and dopamine is derived from which a.a.?

A

phenyalanine (–>tyrosine)

108
Q

melanin is derived from which a.a.?

A

phenyalanine (–>tyrosine)

109
Q

NE is derived from which a.a.?

A

phenyalanine (–>tyrosine)

110
Q

Epi is derived from which a.a.?

A

phenyalanine (–>tyrosine)

111
Q

RA: trmt for PKU

A

decrease phenyalanine
increase tyrosine
avoid aspartame

112
Q

Cystinuria

enzyme defect?

signs?

diagnostic test

trmt?

A

∆ PCT + intestinal a.a. transporter for cysteine, ornithine, lysine, and arginine - COLA

hexagonal cystine stones

urinary cyanide-nitroprusside test

trmt: alkalinization (K-citrate or acetazolamide) and chelating agents

113
Q

sdafds

A

dafsd

0. Step Ib (19 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions