1
Q
N-formylmethionine (fMet) role
A
- Initiation amino acid in prokaryotes
2. Neutrophil chemotaxis
2
Q
Introns can contain
A
miRNA genes
3
Q
Cistinuria - treatment
A
Urinary alkalization (potassium citrate, acetazolamide), chelation agents (penicillamin)
4
Q
Golgi apparatus function
A
- Modifies N-oligosaccharides on Aspargine
- Adds O-Oligosacch on SERINE + THREONINE
- Adds Mannose-6-p
5
Q
Procollagen bonds
A
hydrogen + disulfide
6
Q
protein synthesis direction
A
N-terminus to C
7
Q
intros sequence
A
GU….AG
8
Q
tRNA activates energy
A
- charging - ATP
- initiation pr synthesis - GTP
- ribosomes translocation - GTP
9
Q
Pyridoxine function
A
- transamination
- decarboxylation
- glycogen phosphorylase
CYSTATHIONE, heme, niacin, HISTAMINE, SERETONIN,, epinephrin, norepin, dopamine, GABA`
10
Q
Tuberous scleoris - phenotype expression features
A
INCOMPLETE PENETRANCE
variable expression
11
Q
Duchenne gait, MCC of death
A
- waddling gait
2. Dilated cardiomyopathy
12
Q
Pompe disease findings
A
- Cardiomyopathy
- hypertr cardiomyopathy
- exercie intolerance
- systemic findings leading to early death
13
Q
HMG-coa reductase regulators
A
+ insulin, T4
- Glucagon, cholesterol
14
Q
ATP production - pathways
A
malate-aspartate –> 32
Glycerol-3-P –> 30
Anaerobic –> 2
15
Q
NADPH is used in
A
- anabolic (not ketones)
- P450
- Respiratory burst
- Glutathione reductase
16
Q
Pyruvate to lactate - major pathway in which tissues
A
- RBCs 2. testicles 3. leukocytes
4. lens 5. kidney medulla 6. cornea
17
Q
inhibitors of every step in REDOX
A
- complex 1 –> rotenone
- complex 2 –> antimycin A
- complex 4 –> cyanide, CO
- complex 5 –> oligomycin
- uncoupling agents –> dinitrophenol, aspirin, thermogenein
18
Q
gluconeogenesis tissues
A
liver
intestine
kidney
19
Q
fatty acids/gluconeogenesis
A
even chain –> cannot produce since only acetyl-coa
odd chain –> yield one propionyl-coa –> succinyl coa –> glucose
20
Q
sites of HM shunts (organs)
A
fatty acid or steroid synthesis
- RBCs
- lactating mammary glands
- liver
- adrenal
21
Q
Tissue with sorbitol dehydrogenase
A
- ovaries
- seminal vesicles
- liver
22
Q
Tissue without sorbitol dehydrogenase
A
- scwann
- retina
- kindey
- lens
23
Q
essential glucogenic ketogenic aminoacids
A
- phenylalanine
- tryptophan
- threonine
- isoleucine
24
Q
hyperammonemia treatment
A
- limit protein
- lactulose
- Neomycin + rifamixin
- Phenylbutyrate or Benzoate –> bind aminoacid + lead to excretion
25
mechanism of hypoglycemia in acyl-coa dehydrogenase deficiency
acyl-coa is a + allosteric regulator of pyruvate carboxylase
26
types of ketone bodies (+ tests)
acetone
acetoacetate
β-hydroxybutyrate (not in urine)
27
MC heart defect in Turner (and ausculation)
bicuspid aortic valve (20-30%) --> early systolic, high frequency click over the riht second intespace
(other heart defect is coartraction 3-10%)
28
familiar hypercholesterolemia - type of mutation
frameshift
29
Syndromes with shortened telomeres
syndromes with premature aging (eg. Bloom syndrome)
30
GAA in frataxin --> ...
decreased translation (NOT TRUNCATED)
31
The low of segregation
Mendel's first law:
gametogenesis within parent organism results in separation of paired alleles so that each offspring inherits only half of each parent's genetic composition
32
Turner - area of coartraction
Preductal
33
CF - infertility
inadequate mesonephric duct development
34
Down syndrom - nondisjunction during
anaph 1 or 2
35
out of frame vs in frame mutation
out of frame --> premature termination
| in frame --> maintains the reading
36
RNA polynerase I vs II vs III according to production
I --> 18S, 5.8S & 28S ribosomal RNA (first 45 that divided)
II --> mRNA, miRNA, snRNA
III --> tRNA, 5S ribosomal RNA (essentail for 60S subunit)
37
presenilin genes ch
presenilin 1 --> ch 14
| presenilin 2 --> ch 1
38
CF vs Primary ciliary dyskinesia according to nasal polyps, digital clubbing
both have
39
palindromic sequence in DNA
reading 5--> 3 in one strand is the same as 5-->3 to the other
40
Lyonization
X-inactivation
Methylated DNA
deacetylated histones
41
Risk factors for molar pregnancy
1. maternal age
2. prior molar pregnancy
3. infertility
4. prior miscarriage
42
MEN 1 ch
| p53 ch
11
| 17
43
pheo vs renal ca in VHL
renal is more common
44
epistasis?
the allele of one gen affects tje phenotypic expression of alleles in another gene
45
primary amenorrhea
absence of menses by age 15 in someone who has normal growth + secondary sexual characteristics or absence of menses by age 13 in girls without 2ry sexual characteristics
46
TATA box location
| CAAT box location
25 bases upstream from the beginning of the coding strand (aka Hogness box)
70-80 bases upstream from the beginning of the coding strand
47
protein kinase regulates the activity of its target proteins by
phosphorylating threonine + serine residues
48
promoter in prokaryotes
Pribnow box (-35)
49
patau vs Down vs edwards according to GI manifestations
Down --> Hirschsprung, duodenal atresia
Patau --> omphalocele
Edwards --> Meckel's, diverticulim
50
mechanism of decreased expression of huntingtin protein in Huntington disease
hypo acetylation of histones
51
beside the others, DOWN also increases the risk for
imperofrate anus, tracheoesophageal fistula, celiac disease
52
Down syndrome - endocrinology + rhematology
1. endocrinology: hypothyroidism, DM1, obesity
| 2. Rhematology: Antlantoaxial instability
53
chorionic villus sampling can be performed at ... (when)
10-14 weeks gestation (it has risks)
54
CFTR modulating medications that that promote its transportation at membrane and enhance its action
1. Lumacaftor (transportation)
2. Ivacaftor (enchantment)
IMPROVE FEV + DECREASED PULMONARY EXACERBATIONS
55
other mutations that cause CF
1. mutation that impairs ATP binding
2. mutation that decreased production of normal CFTR (milder)
3. mutation that impairs CL- conduction through CFTR
4. mutation that cause premature termination o the protein (nonsense, frameshift) (usually seen in Askenazi)
56
polycistronic mRNA
found in bacteria --> multiple open reading frames --> translated into several proteins
(not in human: MONOCISTRONIC mRNA --> only 1 protein)
57
MCC of hair loss in both men and females / mode of inheritance
androgenic alopecia --> polygenic (both hormonal + genetic factors) (esp X, Y, short 20 chromosome)
58
eukariotic cells initiation of translation
- AUG
| - Kozak consensus
59
viral interference?
one virus inhibits replication and/or release of a 2nd virus that is infecting the same cell
60
MCCC sex chrom abnormality in females? / presentation
47 XXX --> usually diagnosed incidentally as the carriers are NORMAL
61
reverse transcriptase of human cells / function / structure
telomerase (RNA depended DNA polymerase
- -> Adds TTAGGG repeats to the 3' end of chromosomes
- -> composed of 2 main subunits: a. telomerase reverse transcriptase subunit b. telomerase RNA compoment
62
Vaginal adenosis
replacement of vaginal squamous epithelium with glandular columnar epithelium. it occurs in female children of women exposed to DES during pregnancy. It is a precursor of clear cell adenocarcimona of vagina
63
Methanol induced blindness
methanol --> formic acid (alcohol dehydrogenase)
64
Renal ammoniogenesesis?
renal tubular epithelial cells: glutamine --> glutamate + ammonium + HCO3 (in response to acidosis)
65
1. characteristic of ANA in RA
| 2. citrullination
1. IgM
2. tissue inflammation --> argining residues in proteins such as vimentin to citrulline --> altered shape of antigen --> immune response generation
66
SnRNAs are synthesized by
| miRNAs are synthesized by
both by RNA pol 2
67
MAO enzyme - origin
mitochondria
68
PCR vs rtPCR according to template
PCR: DNA
rtPCR: cDNA
69
Bloom syndrome
rare AR --> BLM gene (helicase) mutation) --> growth retardation, facial anomalies, photosensitivity skin rash, immunodeficiency (due to ch instability + breakage)
70
nuclear and mit proteins synthesis location
nuclear --> RER
| mit --> cytoplasm
71
fructose metabolism abnormalities - 1. breast milk 2. starch
1. no problem because breast milk contains lactose (gal + glu) and maltose (glu + glu) (formula has sucrose)
it does not contain lactose
2. no problem -> starch has only glu
72
McArdle disease - how to improve symptoms
consume sugar before exercise
73
biotin deficiency - ph?
lactic acidosis
74
rate-limiting step in the synthesis of catecholamines
tyrosine hydroxylase (tyrosine --> DOPA)
75
raw eggs white causes biotin depletion due to
high levels of biotin-binding avidin
76
copper reduction test?
detect reducing sugar (fructose, glucose, galactose) --> non specificg
(urine dipsstick --> specific specific for sugar)
77
the elastic properties of elastin are due to
interchain cross-links involving lysine (lysil oxidase) (desmosine cross links)
78
neurofibrosarcomas
malignant peripheral nerve sheath tumors that arise from neurofibromas
79
lead poisoning - type of protoporphirin
zinc protoporphirin (instead of Fe2+)
80
Dopamine hydroxylase deficiency
rare --> dysautonomia (ptosis, orthostatic hypertension, hypoglycemia, hyponatremia)
81
phenylketonuria - brain hypopigmentation
of catecholaminergic locations:
1. locus ceruleus
2. substantia nigra
3. vagal nucleus dorsalis
82
enzyme with increased activity in Lench-Nuhan syndrome
PRPP amidotransferase
83
carotene is a precursor to
vit A
84
degradation of proteins - location
nuclear + cytoplasmic --> proteosome
| extracellular --> lysosomes
85
miRNA - mechanism
transcription in nucleus (pre mirna) - double strand --> cleaved into short RNA helix by ribonuclease protein (DICER) --> seperation of strands --> bind mRNA --> exact match causes mRNA degradation, partial match causes transnational represion by preventing ribosome + transcription factors to bind (posttranscriptional gene silencing)
86
pellagra mediated dementia
due to neuronal degeneration in the brain + spinal cord, with lesions similar to those in B12 deficiency
87
Arginase deficiency in urea cycle - manifestation/treatment
progressive diplegia, growth delay, abnormal movements (mild or no hyperammonia)
treatment: arginine-free, low-protein diet
88
protein structure - bonds
1ry --> covalent
2ry --> hydrogen
3ry --> ionic, udrophobic, hydrogen, disulfide
89
Tetrahydrobiopterin (BH4)?
cofactor used by hydroxylase enzymes in the synthesis of:
1. Tyrosine
2. Dopamine
3. Seretonin
4. NO
90
Methoglobinemia - skin
cyanosis
91
Methylmalonic acidema?
methylmalonyl-Coa mutase (AR) --> lethargy, vomiting, tachpnea
- -> hyperammonemia, ketotic hypoglycemia, met acidosis
- -> elevated methylmalonic acid + propionic acid
92
essential fructosuria - alternative pathway for fructose metabolsim
fructose --> fructose 6-P (hexokinase) --> enter glycolysis
93
Glutamate - glutamine cycle
in the astrocytes: Glutamate + NH3 --> Glutamine (glutamine synthetase)
in neurons: Glutamine --> glutamate (Glutaminase) --> releasing
94
excess ammonia (eg. cirrhosis) - what happen in astrocytes?
increased glutamine production --> increased intracellular osm --> astrocyte swelling --> impaired glutamine release --> decreased glutamate in neurons --> disruption of excitatory neurotransmission
95
leptin action
acts on the arcuate nucleus of hypothalamus --> inhibit production of neuropeptide Y (decreasing apetite)
also stimulate the production of POMC at the same location
96
acquired obesity - leptin
high leptin --> receptor desensitisation
97
Lac operon - genes and their function
z gene --> β-galactosidase --> lctose to glucose + galactose
y gene --> permease --> transmembrane enzyme --> increases permeability of the cell to lactose
a gene --> β-galactoside transacetylase (unnecessary for lactose metabolism to E-coli
(LAC operon also has promoter region + operator region + regulatory gene (repressor protein))
98
cyanide poisoning - presentation
reddish skin discoloration, tachypnea, headache, tachycardia, nausea/vomiting, confusion, weaknes --> seirzures + cardiovascular collapse
- lactic acidosis, narrowing of venous arterial PO2 gradient
99
Hers disease
liver glycogen phosphorylase deficiency --> hypoglycemia, ketosis, hepatomegaly
100
Spinal muscular atrophy - genes
mutation in Survival motor neuron (SMN1) gene, which encodes a protein involved in assembly of snRNPs in LMN
101
cherry red macula spot in severel sphingolipodosis - mechanism
loss of retinal transparency due to ganglioside buildup in ganglion cells
the center of fovea lacks ganglion cells so the underlying choroid transmits its red color
102
hormone that is increased in low BH4 mediated hyperphenylanemia
prolactin (low dopamine production)
| - even if phenylanine restriction (because BH4 is also cofactor of tyrosine hydroxylase)
103
Lynch syndrome - genes (and their function)
mutation of methylation of:
1. MSH2 (code MutS) --> detects mismatch
2. MLH1 (code MutL) --> after detection --> slides along DNA
104
amatoxin - symptoms, diagnosis
6-24h after ingestion --> abdominal pain, vomiting, severe cholera-like diarrhea that may contain blood + mucus, acute hepatic + renal faulre
diagnosis: urine test
105
enzyme that contribute to ketongensis + maintains glucose level in fasting
hormone sensitive lipase -->
a. glycerol to glucose (glycerol kinase)
b. Fatty acids to ketone bodies
106
maturity onset diabetes of the young - presentation
mild nonprogressive hypoglycemia that often worsens with pregnancy-induced insulin resistance --> if homozygous --> fetal growth retardation + severe hypoglycemia in birth
107
Ricin?
from castor oil plant Rinicus commus --> potent toxin that inhibits protein synthesis by cleaving the rRNA component of the eukaryotic 60S subunit
108
synchronisation of of glycogen degradation with skeletal muscle contraction occurs due to
release of sarcoplasimic calcium releasing --> phosphorylase kinase --> glycogen phosphorylase --> increased glyocogenolysis
109
liver - ketone using for enegy
cannot because it lacks succinyl coa acetoacetate CoA tranferae (thiophorase) which is required to convert acetoacetate to acetoacetyl coa
Biochemistry FA
flashcards
Decks in class (16)
# Cards
-
Molecular + cellular428
-
Nutrition143
-
Genetics59
-
Autosomal Dominant Diseases40
-
Cystic Fibrosis, other AR diseases, mascular dystrophies and other X link disorder68
-
Down Syndrome60
-
Glycogen44
-
Metabolism, Enzymes76
-
Glycolysis, TCA cycle, pyruvate, electron transport chain76
-
Gluconeogenesis, HMP Shunt88
-
Amino Acids120
-
Lysosomal Storage Diseases49
-
Fatty Acid Metabolism / Ketone Bodies / lipid transport82
-
Other109
-
other 215
-
vitamins31
