Biochemistry Flashcards
1
Q
what phase of the cell cycle does this drug target:
methotrexate
A
S-phase
2
Q
what phase of the cell cycle does this drug target:
5-fluorouracil
A
S-phase
3
Q
what phase of the cell cycle does this drug target:
hydroxyurea
A
S-phase
4
Q
what phase of the cell cycle does this drug target:
bleomycin
A
G2 phase
5
Q
what phase of the cell cycle does this drug target:
paclitaxel
A
M phase
6
Q
what phase of the cell cycle does this drug target:
vincristine
A
M phase
7
Q
what phase of the cell cycle does this drug target:
vinblastine
A
M phase
8
Q
what phase of the cell cycle does this drug target:
cyclophosphamide
A
non cell cycle specific
9
Q
what phase of the cell cycle does this drug target:
cisplatin
A
non cell-cycle specific
10
Q
base?
A
adenine
11
Q
base?
A
guanine
12
Q
base?
A
cytosine
13
Q
base?
A
uracil
14
Q
base?
A
thymine
15
Q
what are the 3 positive charged amino acids?
A
lisine, arginine, histidine
16
Q
mutation that causes sickle cell anemia
A
missense mutation
glu β> val
17
Q
mutation that causes a-thalassemia
A
unequal crossover
chromosome 16
18
Q
mutation that causes cri-du-chat
A
unequal crossover
(p arm) chromosome 5
19
Q
mutation that causes b-thalassemia
A
splice site mutation
20
Q
stop codons
A
UAA
UGA
UAG
21
Q
start codon
A
AUG (rna)
ATG (dna)
22
Q
codon that codes for glutamine
(typically affected in mutations)
A
CAG
23
Q
codon repeated in:
fragile x syndrome
A
CGG
24
Q
codon repeated in:
myotonic dystrophy
A
CTG
25
codon repeated in:
freidreich's ataxia
GAA
26
codon repeated in:
huntington's
CAG (glutamine)
27
codon repeated in:
spinobulbular muscular atrophy
CAG (glutamine)
28
in what stage and through what mechanism do pseudomonas and diphteria toxins inhibit eukaryotic protein synthesis?
elongation:
β eEF-2 through ADP-ribosylation
29
through what mechanism do shiga and shiga-like toxins inhibit eukaryotic protein synthesis?
clip adenine residue in the 28S rNA
30
what is N- glycosilation?
addition of sugar to the **n**itrogen of **asparginine** residues of the protein
31
what is O-glycosilation?
addition of sugar to the **OH** groups of **serine** and **threonine** residues of the protein
32
what is prenylation?
its a covalent modification on proteins
addition of geranylgeranyl or farnesyl **lipid** groups on membrane-associated proteins so they can bind to cell membrane.
33
zellweger syndrome
pathophysiology and presentation
mutation in genes involving peroxisome biosynthesis --\> defect in fefflux of fatty acids from peroxisiome
presentation:
* enlarged liver
* accumulation of Fe and Cu
* vision problems
* death withn the first year
34
what are the AA with aromatic side-chains?
phenylalanine
tyrosine
tryptophan
35
what are the important derivatives of phenylalanine?
tyrosine (by hydroxylating phenylalanine)
catecholamines!
36
what are the hydrophobic non polar AA with aliphatic side chains?
* valine, leucine, isoleucine
* glycine, proline
* alanine
37
what are the derivatives of tryptophan?
serotonin and niacin
38
what are the 3 AA involved in maple syrup disease?
isolucein, leuceine, valine
39
what is the AA that is only present in collagen?
proline β hydroxiproline
40
π© AA in starving conditions
alanine
41
what are the basic AA?
hydrophilic + charged:
lysine, arginine, histidine
*βhis lines are basicβ*
42
what are the acidic AA?
hydrophilic, - charged :
aspartate (aspartic acid), glutamate (glutamic acid)
43
what are the hydrophilic polar, uncharged R group AA?
serine, theronine, asparagine
cysteine, methionine,
glutamine
44
what are the derivatives of arginine?
creatinine, urea, nitric oxide
45
what is the physiological significance of glutamine?
nitrogen metabolism
carrier of ammonia in the blood to the kidney
46
what are the derivatives of glutamate?
GABA, glutathione
47
what are the essential amino acids?
*βTIM HaLL Punts Very Toughβ*
48
which are the glycogenic and ketogenic aa?
49
vitamin B1
thiamine
50
disease/sx associated with deficiency of biotin
βbald body builderβ
excessive consumption of raw eggs β alopecia
51
vitamin B1
thiamine
52
disease/sx associated with deficiency of thiamine
**ALCOHOLISM**
* Wernicke Encephalopathy
* Korsakoff Syndrome
* Beri-Beri (Dry/Wet)
53
enzyme reactions that require thiamine as a cofactor
54
wernicke encephalopathy triad
1. confusion
2. ophthalmoplegia
3. ataxia
55
Korsakoff syndrome sx
* permanent amnesia
* confabulation
* personality changes
56
dry beriberi
polyneuropathy with symmetric muscle waisting
57
wet beriberi
58
wet beriberi
high-output cardiac failure (dilated cardiomyopathy)
59
vitamin B3
niacin
60
disease/sx associated with deficiency of niacin + sx
**PELLAGRA**
* diarrhea
* dementia
* dermatitis
* death
61
disease/sx associated with deficiency of pyridoxine
sideroblastic anemia β accumulation of iron in the mitochondria
62
π© magenta colored tongue
riboflavin (B2) deficiency
63
π© bitot spots
keratin debris in the eyes
VITAMIN A DEFICIENCY
64
cause of permanent neonatal type 1 diabetes?
near complete glucokinase deficiency
65
sx of pyruvate kinase deficiency?
hemolytic anemia
accumulation of 2,3BPG
no Heinz bodies
66
what is the cause of hereditary fructose intolerance?
aldolase B deficiency
67
cofactors and coenzymes used by pyruvate dehydrogenase
βTender Loving Care For Nancyβ
68
π© blue sclerae
osteogenesis imperfecta
69
what are the 6 types of glycogen storage diseases?
*βVice President Can't Accept Money, Honeyβ*
I: Von Gierke
II: Pompe
III: Cori
IV: Andersen
V: McArdle
VI: Hers
70
π© second wind phenomenon
**McARDLE DISEASE**
(type V glycogen storage disease)
specially I accompanied by
**m**uncle cramps and **m**yoglobinuria
71
π© garlicky breath
Se toxicity
72
what is the #1 cause of hemolytic anemia?
glucose 6P dehydrogenase deficiency
(no conversion of glucose 6P with NADPH byproduct)
73
what is the cause of chronic granulomatous disease?
NADPH oxidase deficiency
74
cause + consequence of familial hypercholesterolemia
**defect in LDL-receptor gene expression**
cool can't be taken up β hypercholesterolemia
de novo synthesis can't be inhibited β hypercholesterolemia
75
π© red-orange eruptive xanthomas
primary hyperlipidemia type I
76
π© xanthomas of the achilles tendon
primary hyperlipidemia type IIa
(familial hypercholesterolemia)
77
π© corneal arcus
primary hyperlipidemia type IIa
(familial hypercholesterolemia)
78
how do we ddx between myopathic CAT/CAT deficiency and McArdle Disease?
biopsy:
McArdle β β muscle glycogen
CAT deficiency β β muscle triglyceride
79
π© dicarboxilic acid in the blood
MCAD deficiency (deficiency in medium chain acyl-CoA dehydrogenase β faulty b-oxidation)
80
π© β C8-C10 acyl carnitines in the blood
MCAD deficiency (deficiency in medium chain acyl-CoA dehydrogenase β faulty b-oxidation)
81
what are the 3 ABC carboxylates?
pyruvate carboxylase
acetyl-CoA carboxylase
propionyl-CoA carboxylase
**A**TP
**B**iotin
**C**O2
82
π© methylmalonic aciduria
vitamin B12 deficiency or
methylmalonyl-CoA mutate defect
(no conversion of methylmalonyl-CoA into succinylcholine-CoA)
83
what enzyme is missing, what substrate accumulates?
tay-sach's disease
hexoaminidase A β ganglioside GM2
84
what enzyme is missing, what substrate accumulates?
gaucher
glucocerebrosidase β glucocerebroside
85
what enzyme is missing, what substrate accumulates?
niemann-pick
sphingomyelinase β sphingomyelin
86
π© cherry red spots in the macula
tay-sachs (+ blindness and psychomotor retardation)
OR
neimann-pick (+hepatosplenomegaly, mental retardation)
87
π© crumpled paper inclusions
gaucher disease
88
what enzyme is missing, what substrate accumulates?
fabry
alpha-galactosidase A β ceramide trihexoside globotriaosylceramide
89
Ι1-antiptrypsin deficiency (cause)
point mutation that causes the Ι1-antiptrypsin to missfold and aggregate in the ER and damage cells (cirrhosis + fibrosis)
90
hartnup disease (cause + sx)
deficiency in receptor that absorbs large AA including tryptophan
pellagra like sx
91
cysteinuria (cause, findings, tx)
defect in receptor that absorbs basic AA + cysteine
cystine accumulates
azetazolamide
92
π© orotic acid
ornithine transcarbomylase deficiency (genetic deficiency or urea synthesis)
93
π© musty odor in diapers
phenylketonuria
94
π© blue or black urine
alkaptonuria
95
π© port-wine urine / red-brown urine
porphyria
+ photosensitivity -β porphyria cutΓ‘nea tarda
96
π© siderroblasts in bone marrow
lead poisoning
OR
B6 (pyridoxine) deficiency
97
π© hemosiderin
(precipitated ferritin in the blood)
iron overload β **hemochromatosis**
98
what is the enzyme that conjugates bilirubin?
UDP-glucorynil transferase
99
π© clay colored stools
bile obstruction
100
lesch-nyhan syndrome
HGPRT deficiency
(no salvage of purines)
101
what does adenosine deaminase deficiency cause?
severe combined immunodeficiency
102
what is the effect of xanthine oxidase on 6-mercaptopurine?
deactivates it β hyperuricemia
103
what enzyme is required for the activation of 6-mercaptopurine?
HGPRT
104
crigler-najjar syndrome
severe congenital jaundice due to defect in UDP-glucoronyl transferase
105
gilbert syndrome
below optimal function of UDP-glucoronyl transferase
benign, no jaundice
106
autoimmune polyendocrine syndrome (triad)
mutation in autoimmune regulator gener (AIRE)
1. mucocutaneous candidiasis
2. hypoparathyroidism
3. adrenal failure
107
π© corkscrew hair
**vitamin C deficiency**
+ bleeding/swollen gums, easy bruising, petechiae, hermarthorsis/hemorrhages
108
why does MCAD deficiency cause hyperammonemia
109
π© needle shaped, negatively birefringent crystals
monosodium urate crystals β GOUT
110
π© jaundice in the presence of sulfa drugs
hemolytic anemia (G6PD deficiency)
111
π© mammilary body atrophy on MRI
advanced wernicke-korsakoff
112
hypotonia + hypoketoic hypoglycemia + dilated cardiomiopathy
carnitine uptake deficiency or VLCAD deficiency (if carnitine esters are found)
113
π© bite cells
G6PD deficiency
from the phagocytosis of Heinz bodies
114
what are the 2 types of SCID?
ADA deficiency (AR) β low B&T cells,
IL2RG mutation (X-linked recessive) β dysfunctional B cells
115
inheritance pattern of G6PDH deficiency
X-linked
116
π© poor wound healing (trace element)
**zinc**
+ stomatitis, alopecia
117
mx associated with hyperuricemia and increased risk of gout
*Painful Tophy and Feet Need Care*
Pyrazinamide
Thiazides
Furosemide
Niacine
Cyclosporine
118
what compounds are metabolized into propionyl-CoA
*VOMIT*
Valine
Odd-chain fatty acids
Methionine
Isoleucine
Threonine
\*not leucine!
119
π© octanoyl-glycine in the blood
MCAD deficiency
120
π© red/orange crystals in urine
βsand" crystals in diapers
HGPRT deficiency β **Lesch Nyhan Syndrome**
121
bloom syndrome (cause)
BLM gene mutation β deficient helicase
122
π© pythanic acid build up (+ other sx)
**refsum disease** (a-oxidation disorder)
* shortening of the 4th toe
* scaly skin
* epiphyseal displasia
* cataracts
123
adrenoleukodystrophy (cause + sx)
x-linxed disorder of B-oxidation (ABCD1 gene)
* accumulation of VLCFA in:
* adrenal glands
* white matter of the brain
124
presentation of riboflavin deficiency
125
which vitamin can be used to tx dyslipidemia?
niacin
126
podagra
B3 over-dose *βOh Dearβ*
facial flushin
hyperglycemia
hyperuricemia
127
fomepizol (use + mechanism of action)
methanol + ethylene glycol over dose
competitive inhibitor for alcohol dehydrogenase
128
tissue in which sorbitol accumulates
*LARKS*
Lens
*A β aldose reductase present*
Retina
Kidneys
Schwann Cells
129
clinical presentation of homocysteinuria
130
π© build up of VLCFA
peroxisome disorders
* zellwegger syndrome
* adrenoleukodystrophy
* refsum disease
131
warburg effect
use of anaerobic glycolysis in stem or cancer cells despite adequate oxygen level which results in increased lactate
132
stress hyperglycemia
elevated blood glucose in the context of sever illness in pts without preexisting DM
due to the secretion of stress hormones
133
hunter syndrome
| (pres, enzyme deficiency, substrate that accumulates, inheritance)
*βhunters see clearly and aggressively aim for the Xβ*
134
hunter syndrome
| (pres, enzyme deficiency, substrate that accumulates, inheritance)
135
reactions dependent on BH4
phenylalanine β tyrosine β DOPA
tryptophan β serotonin
arginine β NO
136
π© cheilosis + stomatitis + glossitis
riboflavin deficiency
137
what does a-amantadin inhibit?
RNA polymerase II which makes mRNA, snRNA and hnRNA
138
π© abnormal pallor of catecholaminergic brain nuclei on autopsy
phenylketonuria
139
π© hyperphenylalaninemia + elevated prolactin
dehydrobipterin reductase
140
π© neutral amino aciduria
hartnup disease
no absorbtion of neutral amino acids (tryptophan)
pellagra like sx + cerebellar ataxia
