Biochemistry Flashcards
1
Q
Type I collagen
A
Bone, skin, tendon, dentin, fascia, cornea, late wound repair
2
Q
Type II collagen
A
Cartilage
3
Q
Type III collagen
A
Reticulin, skin, blood vessels, uterus, fetal tissue, granulation tissue
4
Q
Type IV collagen
A
Basement membrane, basal lamina, lens
5
Q
What reflects collagen synthesis?
A
Gylcine content
6
Q
Process of collagen modification
A
hydroxylation, glycosylation, exocytosis, proteolytic processing, cross linking
7
Q
collagen hydroxylation
A
proline, lysine, requires vitamin C
8
Q
what is glycosylated in collagen?
A
pro-a chain hydroxylysine
9
Q
problems forming collagen glycosylated triple helix
A
osteogenesis imperfecta
10
Q
processing of collagen
A
cleaavage of disulfide rich terminal regions
11
Q
collagen process
A
procollagen –> insoluble tropocollagen –> collagen fibrils
12
Q
tropocollagen –> collagen
A
lysine-hydrolysine cross linking
13
Q
problem with collagen cross linking
A
Ehlers-Danlos syndrome
14
Q
COLIA1/2
A
Osteogenesis imperfecta
15
Q
Osteogenesis imperfecta usually due to
A
decreased production of type I collagen
16
Q
blue sclerae
A
osteogenesis imperfecta
17
Q
inheritance OI
A
AD
18
Q
inheritance Ehlers-Danlos
A
AD or AR
19
Q
Vascular type Ehlers-Danlos
A
deficient type III collagen
20
Q
Menkes disease inheritance
A
XR
21
Q
Menkes disease
A
Impaired Cu absorption and transport
22
Q
ATP7A
A
Menkes protein
23
Q
brittle hair, growth retardation, hypotonia
A
Menkes disease
24
Q
decreased activity of lysyl oxidase
A
Menkes disease due to no CU
25
Elastin rich in
proline, glycine, ltsine
26
fibrillin scaffolding with
tropoelastin
27
Marfan
defect in fibrillin in elastin
28
PCR needs
heat (95C), DNA primers, tRNA, DNA polymerase
29
Southern blot
DNA cleaved, radiolabeled DNA, complementary strand
30
Northern blot
used RNA sample, for mRNA and therefore gene expression
31
Western blot
Antibody binds relevent protein
32
Southwestern blot
Oligonucleotide probe, finds DNA binding proteins
33
Flow cytometry
Assesses immunophenotype of cells in a sample
34
ELISA
presence of antigen/antibody using enzyme producing colour change
35
Karyotyping uses what stage?
Metaphase
36
FISH
localises gene on chromosome
37
Cloning needs
mRNA, reverse transcriptase, --> cDNA --> plasmid
38
Cre-lox system
inducibly manipulates genes at specific developmental points
39
Not all individuals with a mutation show the mutation phenotype
Incomplete penetrance
40
Pleiotropy
One gene contributes to multiple phenotypic effects
41
e.g. of anticipation
Huntingdon's
42
Loss of heterozygosity
A hit on each allele is needed
43
Dominant negative mutation
nonfunctional protein which also prevents the normal gene from working
44
e.g. Mosaicism
McCune-Albright syndrome
45
McCune-Albright syndrome
G protein signalling
46
Locus heterogeneity
mutations at different loci can produce a similar phenotype
47
Allelic heterogeneity
different mutations in the same locus produce the same phenotype
48
Heteroplasmy
normal and mutated mtDNA, variable expression of mt disease
49
Uniparental disomy types
2 chr from one parent, none from the other
50
Heterodisomy
meiosis I error
51
Isodisomy
meiosis II error
52
Frequency of X linked recessive in males and females
```
M = q
F = q^2
```
53
Imprinting
one allele is inactive from methylation
54
e.g. of maternal Imprinting
Prader-Willi
55
Prader-Willi
mom gene silent, dad gene deleted/wrong
56
Angelman syndrome
dad gene silent, mom gene deleted/ gone wrong
57
hyperphagia, obesity, intellectual disability, hypogonadism, hypotonia
Prader-Willi
58
inappropriate laughter, seizure, ataxia, severe intellectual disability
Angelman syndrome
59
e.g. X linked dominant
Hypophosphatemic rickets, Rett syndrome, fragile X syndrome, Alport syndrome
60
Muscle fibres show ragged red fibres
Mitochondrial myopathy
61
Achondroplasia
fibroblast GF 3 mutation, inhibits chondroblasts
62
AD PKD
PKD1 gene on chr.16; PKD2 gene on chr.4
63
Familial adenomatous polyposis
APC genes on chr.5q
64
Familial hypercholesterolaemia
defective/absent LDL receptor; corneal arcus, tendon xanthoma
65
Hereditary hemorrhagic telangiectasia also known as
Osler-Weber-Rendu syndrome
66
branching skin lesions, epistaxis, skin discolourations, ateriovenous malformations, GI bleeding, henaturia
hereditary haemorrhage telangiectasia
67
ankyrin or spectrin defect
Hereditary spherocytosis
68
Huntingdon chr.
4
69
Li-Fraumeni syndrome
TP53 abnormality
70
Sarcoma, breast cancer, leukaemia, adrenal gland cancer
Li-Fraumeni syndrome
71
Marfan
FBN1 gene mutation chr.15
72
lens subluxation - condition and direction
Marfan's; upward and temporally
73
MEN 2A and 2B
RET gene
74
cafe-au-lait spots, neurofibromas, optic glioma, phaeochromocytoma, Lisch nodules
Neurofibromatosis type 1
| chr.17
75
bilateral acoustic schwannoma, juvenile cateracts, meningioma, ependymoma
neurofibromatosis 2
| chr. 22
76
numerous benign harmatomas
tuberous sclerosis
77
deletion of VHL gene - name and chr.
von Hippel-Lindau
| chr.3
78
most common problem in CF
phe508 deletion
79
What does CF cause
decreased Cl and H2O secretion
80
Sweat test for CF value
>60
81
newborn screening CF
immunoreactive trypsinogen
82
Fabry disease
XLR
83
Ornithine transcarbamylase deficiency
XLR
84
Ocular albinism
XLR
85
G6PD deficiency
XLR
86
Hunter syndrome
XLR
87
Bruton agammaglobulinaemia
XLR
88
Lesch-Nyhan syndrome
XLR
89
Duchenne and Becker muscular dystrophies
XLR
90
Cause of duchenne muscular dystrophy
frameshift, no dystrophin, muscle can't regenerate
91
cause of death in duchenne muscular dystrophy
commonly dilated cardiomyopathy
92
where does weakness begin in duchenne muscluar dystrophy?
pelvic girdle
93
What is seen with lack of dystrophin
raised CK and aldolase
94
Becker dystrophy
insertion into dystrophin gene
95
DMPK gene CTG repeat called, causes
myotonic type 1 muscular dystrophy, abnormal myotonin protein kinase
96
myotonia, muscle wasting, cataracts, testicular atrophy, frontal balding, arrhythmia
myotonic type 1 muscular dystrophy
97
FMR1 gene
fragile X syndrome, CGG repeat
98
enlarged testes, long face, large jaw, large everted ears, autism, mitral valve prolapse
fragile X syndrome
99
GAA repeat
Freidrich ataxia
100
meiotic nondisjuction
Down's syndrome
101
nuchl translucency, hypoplastic nasal bone
Down's syndrome
102
raised free b-hCG
Down's syndrome
103
raised inhibin A
down's syndrome
104
decreased a-fetoprotein
down's syndrome
105
decreased estroil
down's syndrome
106
rocker bottom feet, small jaw, low set ear, crossed fingers
Edward's 18
107
decreased PAPP-A, b-HCG
Edward's, Patau's
108
Rocker bottom feet, microcephaly, cleft lip, congenital heart disease, cutis aplasia, microphthalmia
Patau 13
109
Robertsonian translocation chromasomes
13, 14, 15, 21, 22
110
deletion of short arm on chr.5
cri-du-chat syndrome
111
microcephaly, intellectual disability, high-pitched crying, epicanthal folds, VSD
cri-du-chat
112
deletion of long arm of chr.7
William's syndrome
113
elfin face, intellectual disability, hypercalcemia, verbal stills, friendliness with strangers, CVS issues
William's syndrome
114
thymic aplasia, cleft palate, cardiac defect, hypocalcaemia
22q11 delection syndromes
115
22q11 deletion syndromes
DiGeorge syndrome, Velcardiofacial syndrome
116
Fat soluble vitamins
A, D, E, K
117
B12 storage
liver 3-4 yrs
118
B9 storage
liver 3-4 months
119
dermatitis, glossitis, diarrhea
B complex deficiencies
120
Function of vitamin A
differentiation of epithelial cells
121
retinol
vitamin A
122
vitamin A found in
liver, leafy veg
123
all-trans retinoic acid
Acute promyelocytic leukaemia
124
dry scaly skin, night blindness, bitot spots
vitamin A deficiency
125
vitamin A toxicity
vertigo, blurred vision, alopecia, dry skin, hepatic toxicity, tetarogenic
126
B1 name
thiamine
127
B1 cofactors
pyruvate dehydrogenase, a-ketoglutarate, transketolase, branched chain ketoacid dehydrogenase
128
B1 Deficiency
Beri-beri, Wernicke-Korsakoff syndrome
| Impaired glucose breakdown
129
Dry beri beri
polyneuritis, symmetrical muscle wasting
130
Wet beri beri
high-output cardiac failure
131
If suspecting B1 deficiency don't give
glucose infusion
132
riboflavin
B2
133
B2 function
redox reactions - FAD and FMN
134
Cheilosis, corneal vascularisation
B2 deficiency
135
Niacin
B3
136
B3 function
NAD, NADP
137
B3 made from
tryptophan, B2 + B6
138
lowers VLDL, raises HDL
B3
139
glossitis, pellagra
B3 defieiency
140
pellagra symptoms
diarrhoea, dementia, dermatitis
141
broad collar rash
dermatitis from B3 deficiency
142
Hartnup disease
defieincy of neutral a.a. transporters in kidney and gut
143
Rx Hartnup disease
high protein, nicotinic acid
144
prostaglandin facial flushing Rx
aspirin + B3
145
pantothenic acid
B5
146
B5 function
coenzyme A
147
dermatitis, enteritis, alopecia, adrenal insufficiency
B5 deficiency
148
Pyridoxine
B6
149
B6 function
transamination, decarboxylation, phosphorylation cofactor
150
Pyridoxal phosphate
from B6
151
B6 needed for
cystathionine, heme, niacin, histamine, neutotransmitters
152
convulsions, hyperirritability, peripheral neuropathy, sideroblastic anaemia
B6 deficiency
153
Biotin
B7
154
function of B7
cofactor for carboxylases
155
excessive ingestion of raw egg whites
B7 deficiency
156
antibiotic use
B7 deficiency
157
folate
B9
158
function of B9
synthesis of DNA/RNA
159
absorption of B9
jejunum
160
increased homocystine, normal methylmalonic acid
b9 deficiency
161
drugs causing B9 deficiency
phenytoin, sulfonamides, methotrexate
162
Cobalamin
B12
163
cofactor for methionin synthase
B12
164
degeneration of dorsal columns, lateral corticospinal tract, spinocerebellar tract - from
b12 deficiency
| abnormal myelin
165
aids iron absorbtion
vitamin C
166
dopamine B-hydroxylase
needs vitamin C
167
corkscrew hair
scurvy
168
scurvey comes from
collagen synthesis defect
169
calcium oxalate nephrolithiasis
excess vitamin C
170
ergocalciferol
D2
171
cholcalciferol
D3
172
storage vitamin D
25-OH D3
173
tocopherol/ tocotrienol
vitamin E
174
what do you not give with vitamin E?
warfarin - enhances anticoag effect
175
looks like B12 deficiency, no megaloblastic anaemia
vitamin E deficiency
176
phytomenadione, phylloquinone, phytonadione
vitamin K
177
carboxylation glutamic acid residues
vitamin K
178
newborn injection of vitamin K
intestines are unable to synthesise vitamin K
179
delayed wound healing, hypogonadism, decreased adult hair, dysgeusia, anosmia, acrodermatitis
zinc deficiency
180
Kwashikor
protein deficiency
181
Marasmus
malnutrition --> muscle wasting
182
Fomepizole
inhibits alcohol dehydrogenase
| antidote for methanol/ ethylene glycol poisoning
183
Inhibits acetaldehyde dehydrogenase
disulfiram
184
where does B oxidation occur?
mitochondria
185
where does glycolysis occur?
cytoplasm
186
which processes occur in both the mitochondria and cytoplasm?
heme synthesis
urea cycle
gluconeogenesis
187
difference between kinase and phosphorylase
both transfer phosphate groups, kinase requires ATP
188
what is the rate determining enzyme in glycolysis
PFK-1
189
what is the rate determining enzyme in gng
fructose-1,6-biphosphatase
190
what is the rate determining enzyme in TCA
isocitrate dehydrogenase
191
what is the rate determining enzyme in glycogenesis
glycogen synthase
192
what is the rate determining enzyme in glycogenolysis
glycogen phosphorylase
193
what is the rate determining enzyme in HMP shunt
G6PD
194
what is the HMP shunt?
pentose phosphate pathway
195
what is the rate determining enzyme in de novo pyrimidine synthesis
PRPP aminotransferase
196
what is the rate determining enzyme in the urea cycle
carbamoyl phosphate synthetase I
197
what is the rate determining enzyme in fatty acid synthesis
Acetly-CoA carboxylase
198
what is the rate determining enzyme in fatty acid oxidation
carnitine acyltransferase
199
what is the rate determining enzyme in ketogenesis
HMG-CoA synthase
200
what is the rate determining enzyme in cholesterol synthesis
HMG-CoA reductase
201
malate aspartate shuttle produces, from
32 ATP; liver, heart
202
glycerol-3-phosphate shuttle produces, from
30 net ATP; muscle
203
how does arsenic work?
glycolysis produces 0 ATP
204
how much ATP is made in anaerobic exercise?
2 ATP per glucose
205
electron acceptor in catabolic processes
NAD
206
electron acceptor used in anabolic processes
NADPH
207
glucokinase
Liver, B cells of pancreas, ?kidney
208
hexokinase
most tissues except liver, B cells of pancreas
209
MODY diabetes
mutation in glucokinase
210
pyruvate dehydrogenase complex deficiency causes a build up of
lactate and alanine
211
Rx pyruvate dehydrogenase complex deficiency
high fat, lots of lysine and leucine
212
TCA mneumonic
Citrate Is Krebs Starting Substrate For Making Oxaloacetate
213
How much ATP is made in 1 TCA?
10
214
DNA polymerase I found in
Prokaryotes
215
What inhibits prokaryotic topiosmoerases?
Fluroquinolones (II - DNA gyrase)
216
what do tRNA wobbles cause?
silent mutations
217
DNA ligase action
forms phosphodiester bond
218
Primase
makes RN primer on which DNA polymerase III can initiate replication
219
Transversion mutation
purine pyramidine
220
DNA topiosomerases
create single or double stranded break in the helic to add or remove supercoils
221
DNA polymerase III
elongates from 3'
| proofreads 5' --> 3'
222
Transition mutation
purine to purine
| pyramidine to pyrimadine
223
Helicase
unwinds DNA at replication fork
224
What inhibits eukaryotic topioisomerases?
etoposide/ teniposide (II)
225
action of DNA polymerase I
degreades RNA primer, replaces it with DNA
226
What does RNA polymerase I make?
rRNA
227
What does RNA polymerase II make?
mRNA
228
What way is protein synthesis?
N to C
229
mRNA start codon
AUG (GUG)
230
What a.a does AUG code for? (2)
Eukaryotes - methionine
| Prokaryotes - N-formylmethionine (f-Met)
231
What is defective in Lynch syndrome?
Mismatch repair
232
Nucleoside excision and repair done by
DNA polymerase and ligase
233
What does fMet stimulate?
neutrophil chemotaxis
234
What carries out base excision repair?
AP-andonucleases - 5'
Lyase 3'
DNA polymerase-B
DNA ligase
235
What is defective in xeroderma pugmentosum?What is the cause?
Nucleoside excision repair
| UV light
236
e.g. of Frameshift mutation
Duchenne muscular dystrophy
| Tay-Sachs
237
What signals the end of a gene?
Lots of As and Ts
238
mRNA stop codons
UGA, UAA, UAG
239
what does a nonsense mutation result in?
an early stop codon
240
splice site mutation
retains an intron
241
Where does RNA polymerase II bind?
Promoter region
242
mechanism rifampicin
inhibits RNA polymerase in prokaryotes
243
mechanism actinomysin D
inhibits all RNA polymerases
244
what is the mRNA quality control?
P-bodies in the cytoplassm
245
What is different about eukaryotic and prokaryotic RNA polymerase?
Only P proofreads
246
What is the function of snRNPs?
to splice introns
247
a-amanitin
death cap mushrooms inhibiting RNA polymerase II
248
polyadenylation signal
AAUAAA
249
When does hnRNA become mRNA?
When it has been capped, spliced and tailed
250
What does RNA polymerase II make?
5s rRNA, tRNA
251
what comes before mRNA
hnRNA, heterogenous nuclear RNA
252
what are the two parts of tRNA?
T arm
| D arm
253
mischarged tRNA synthetase
reads usual codon but inserts wrong amino acid
254
WHat does the T-arm contain? What is the functoin?
ribothymidine, pseudouridine cytidine
| ribosome binding
255
what is a the 3' end of tRNA?
CCA
256
function of ribozymes
cacalyse peptied bond
257
how is protein synthesisi initiated?
GTP hydrolysis
258
prokaryote subunits
30S + 50S --> 70S
259
eukaryote subunits
40S + 60S --< 80S
260
tumour supressor chain
p53 --> p21 --> inhibition of CKDs
261
posttranslational trimming
removal of N or C terminal propeptides from xymogen
262
cyclin function
control cell cycle events, activate CKDs
263
e2f
transcription factor inhibiting G1-S progression
264
microfilaments
contraction
265
intermediate filaments
maintain cell structure
266
labile cell types
divide rapidly, always in G1
267
smooth ER
steroid synthesis, detoxification
268
permanent cell types
remains in G0, regenerate from stem cells
269
Nissl bodies
rough ER in neurones
270
Rough ER
site of exported protein protein synthesis
271
Microtubules e.g.
cilia, flaggela, mitotic spindle, axonal trafficking, centrioles
272
stable cell tpyes
quiescent --> G1 on stimulation
273
Peroxisome
very long chain/ branched fatty acid degredation, a.a, ethanol, B oxidation
274
vimentin, desmin, cytojeratin, lamins, glial fibrillary acid proteins, neurofilaments
intermediated illaments
275
golgi amino acid modifications
asparganin - N-oligosaccherides serine, threonine - O-oligosaccherides
276
Desmin
muscle
277
Ergosterol
found in the plasma membrane of fungi
278
Kartagner syndrome
primary ciliary dyskinesia
279
Type I collagen
90%
| bone, skin, tendon, dentin, fascia, cornea, late wound repair
280
Kinesin
-+ anterograde
281
Dunein
+- retrograde
282
9+ microtubule doublets
Cilia
283
Glial fibrillar acid proteins (GFAP)
neuroglia
284
Na/K
3 Na out
| 2 K in
285
Ouabain
inhibits NAK ATPase by binding to K+ side
286
What are microtubules?
polymerised heterodimers
287
Cytokeratin
epithelial cells
288
Vimentin
mesenchymal tissue
289
What energy is used in microtubules?
GTP
290
Drugs acting on microtubules
Mebendazole, griseofulvin, colchicine, vincristine/ vinblastine, paxlitaxel
291
what is the marker for damaged protein?
ubiquitin
292
euchromatin
less condensed
transcriptionally active
sterically acessible
293
Barr bodies
condensed, transcriptionally inactive, inacessible
294
Histone methylation
Not-permanent, can activate
295
Nucleosome =
histone octomers with DNA wrapped around
296
What is methylated?
cytosine and adenine
297
Purines
A
| G
298
Which amino acids are coded for by only one codon
methionine
| tryptophan
299
nucleotide
base + sugar + phsophate
300
purine salvage deficiency
adenosine deaminase deficiency
| lesch-nyhan syndrome
301
which amino acids are histones rich in?
lysine
| arginine
302
Which base bond is stronger
G-C
303
Orange sand nappy
Lesch-Nyhan syndrome
304
What is a major cause of SCID?
Adenoside deaminase deficiency
305
X descent
absent
prominent
atrial relaxation
tricuspid regurg
tricuspid insufficiency, right HF
306
Pyrimadines
CUT
307
e.g. of heterochromatin
Barr boides
308
Methylation and transcription
methylation at CpG islands
| represses transcription
309
What is increased in adenosine deaminase deficiency?
| What does this cause?
dATP
| toxicity in lymphocytes
310
nucleoside
base + sugar
311
what allows histones to be transcribed?
acetylation
312
Which amino acids are needed for purine synthesis?
Glycine
Aspartate
Glutamine
313
What is the replication fork?
Y shaped region between leading and lagging strands
314
Purpose of methylation
ability to distinguish between old and new strands in prokaryotes
315
Cause and Rx maple syrup urine disease
decreased branched-chain a-ketoacid dehydrogenase
| restrict ilo, leu, val; B1 supplements
316
musty body odour
| Rx
phenylketonuria
| increase tyrosine, decrease phenylalanine
317
marfinoid, lens subluxation, kyphosis
| what will you see in urine?
XS homocystine
