Other Flashcards
N-formylmethionine (fMet) role
- Initiation amino acid in prokaryotes
2. Neutrophil chemotaxis
Introns can contain
miRNA genes
Cistinuria - treatment
Urinary alkalization (potassium citrate, acetazolamide), chelation agents (penicillamin)
Golgi apparatus function
- Modifies N-oligosaccharides on Aspargine
- Adds O-Oligosacch on SERINE + THREONINE
- Adds Mannose-6-p
Procollagen bonds
hydrogen + disulfide
protein synthesis direction
N-terminus to C
intros sequence
GU….AG
tRNA activates energy
- charging - ATP
- initiation pr synthesis - GTP
- ribosomes translocation - GTP
Pyridoxine function
- transamination
- decarboxylation
- glycogen phosphorylase
CYSTATHIONE, heme, niacin, HISTAMINE, SERETONIN,, epinephrin, norepin, dopamine, GABA`
Tuberous scleoris - phenotype expression features
INCOMPLETE PENETRANCE
variable expression
Duchenne gait, MCC of death
- waddling gait
2. Dilated cardiomyopathy
Pompe disease findings
- Cardiomyopathy
- hypertr cardiomyopathy
- exercie intolerance
- systemic findings leading to early death
HMG-coa reductase regulators
+ insulin, T4
- Glucagon, cholesterol
ATP production - pathways
malate-aspartate –> 32
Glycerol-3-P –> 30
Anaerobic –> 2
NADPH is used in
- anabolic (not ketones)
- P450
- Respiratory burst
- Glutathione reductase
Pyruvate to lactate - major pathway in which tissues
- RBCs 2. testicles 3. leukocytes
4. lens 5. kidney medulla 6. cornea
inhibitors of every step in REDOX
- complex 1 –> rotenone
- complex 2 –> antimycin A
- complex 4 –> cyanide, CO
- complex 5 –> oligomycin
- uncoupling agents –> dinitrophenol, aspirin, thermogenein
gluconeogenesis tissues
liver
intestine
kidney
fatty acids/gluconeogenesis
even chain –> cannot produce since only acetyl-coa
odd chain –> yield one propionyl-coa –> succinyl coa –> glucose
sites of HM shunts (organs)
fatty acid or steroid synthesis
- RBCs
- lactating mammary glands
- liver
- adrenal
Tissue with sorbitol dehydrogenase
- ovaries
- seminal vesicles
- liver
Tissue without sorbitol dehydrogenase
- scwann
- retina
- kindey
- lens
essential glucogenic ketogenic aminoacids
- phenylalanine
- tryptophan
- threonine
- isoleucine
hyperammonemia treatment
- limit protein
- lactulose
- Neomycin + rifamixin
- Phenylbutyrate or Benzoate –> bind aminoacid + lead to excretion
mechanism of hypoglycemia in acyl-coa dehydrogenase deficiency
acyl-coa is a + allosteric regulator of pyruvate carboxylase
types of ketone bodies (+ tests)
acetone
acetoacetate
β-hydroxybutyrate (not in urine)
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%)
familiar hypercholesterolemia - type of mutation
frameshift
Syndromes with shortened telomeres
syndromes with premature aging (eg. Bloom syndrome)
GAA in frataxin –> …
decreased translation (NOT TRUNCATED)
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
Turner - area of coartraction
Preductal
CF - infertility
inadequate mesonephric duct development
Down syndrom - nondisjunction during
anaph 1 or 2
out of frame vs in frame mutation
out of frame –> premature termination
in frame –> maintains the reading
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)
presenilin genes ch
presenilin 1 –> ch 14
presenilin 2 –> ch 1
CF vs Primary ciliary dyskinesia according to nasal polyps, digital clubbing
both have
palindromic sequence in DNA
reading 5–> 3 in one strand is the same as 5–>3 to the other
Lyonization
X-inactivation
Methylated DNA
deacetylated histones
Risk factors for molar pregnancy
- maternal age
- prior molar pregnancy
- infertility
- prior miscarriage
MEN 1 ch
p53 ch
11
17
pheo vs renal ca in VHL
renal is more common
epistasis?
the allele of one gen affects tje phenotypic expression of alleles in another gene
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
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
protein kinase regulates the activity of its target proteins by
phosphorylating threonine + serine residues
promoter in prokaryotes
Pribnow box (-35)
patau vs Down vs edwards according to GI manifestations
Down –> Hirschsprung, duodenal atresia
Patau –> omphalocele
Edwards –> Meckel’s, diverticulim
mechanism of decreased expression of huntingtin protein in Huntington disease
hypo acetylation of histones
beside the others, DOWN also increases the risk for
imperofrate anus, tracheoesophageal fistula, celiac disease
Down syndrome - endocrinology + rhematology
- endocrinology: hypothyroidism, DM1, obesity
2. Rhematology: Antlantoaxial instability
chorionic villus sampling can be performed at … (when)
10-14 weeks gestation (it has risks)
CFTR modulating medications that that promote its transportation at membrane and enhance its action
- Lumacaftor (transportation)
- Ivacaftor (enchantment)
IMPROVE FEV + DECREASED PULMONARY EXACERBATIONS
other mutations that cause CF
- mutation that impairs ATP binding
- mutation that decreased production of normal CFTR (milder)
- mutation that impairs CL- conduction through CFTR
- mutation that cause premature termination o the protein (nonsense, frameshift) (usually seen in Askenazi)
polycistronic mRNA
found in bacteria –> multiple open reading frames –> translated into several proteins
(not in human: MONOCISTRONIC mRNA –> only 1 protein)
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)
eukariotic cells initiation of translation
- AUG
- Kozak consensus
viral interference?
one virus inhibits replication and/or release of a 2nd virus that is infecting the same cell
MCCC sex chrom abnormality in females? / presentation
47 XXX –> usually diagnosed incidentally as the carriers are NORMAL
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
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
Methanol induced blindness
methanol –> formic acid (alcohol dehydrogenase)
Renal ammoniogenesesis?
renal tubular epithelial cells: glutamine –> glutamate + ammonium + HCO3 (in response to acidosis)
- characteristic of ANA in RA
2. citrullination
- IgM
- tissue inflammation –> argining residues in proteins such as vimentin to citrulline –> altered shape of antigen –> immune response generation
SnRNAs are synthesized by
miRNAs are synthesized by
both by RNA pol 2
MAO enzyme - origin
mitochondria
PCR vs rtPCR according to template
PCR: DNA
rtPCR: cDNA
Bloom syndrome
rare AR –> BLM gene (helicase) mutation) –> growth retardation, facial anomalies, photosensitivity skin rash, immunodeficiency (due to ch instability + breakage)
nuclear and mit proteins synthesis location
nuclear –> RER
mit –> cytoplasm
fructose metabolism abnormalities - 1. breast milk 2. starch
- no problem because breast milk contains lactose (gal + glu) and maltose (glu + glu) (formula has sucrose)
it does not contain lactose - no problem -> starch has only glu
McArdle disease - how to improve symptoms
consume sugar before exercise
biotin deficiency - ph?
lactic acidosis
rate-limiting step in the synthesis of catecholamines
tyrosine hydroxylase (tyrosine –> DOPA)
raw eggs white causes biotin depletion due to
high levels of biotin-binding avidin
copper reduction test?
detect reducing sugar (fructose, glucose, galactose) –> non specificg
(urine dipsstick –> specific specific for sugar)
the elastic properties of elastin are due to
interchain cross-links involving lysine (lysil oxidase) (desmosine cross links)
neurofibrosarcomas
malignant peripheral nerve sheath tumors that arise from neurofibromas
lead poisoning - type of protoporphirin
zinc protoporphirin (instead of Fe2+)
Dopamine hydroxylase deficiency
rare –> dysautonomia (ptosis, orthostatic hypertension, hypoglycemia, hyponatremia)
phenylketonuria - brain hypopigmentation
of catecholaminergic locations:
- locus ceruleus
- substantia nigra
- vagal nucleus dorsalis
enzyme with increased activity in Lench-Nuhan syndrome
PRPP amidotransferase
carotene is a precursor to
vit A
degradation of proteins - location
nuclear + cytoplasmic –> proteosome
extracellular –> lysosomes
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)
pellagra mediated dementia
due to neuronal degeneration in the brain + spinal cord, with lesions similar to those in B12 deficiency
Arginase deficiency in urea cycle - manifestation/treatment
progressive diplegia, growth delay, abnormal movements (mild or no hyperammonia)
treatment: arginine-free, low-protein diet
protein structure - bonds
1ry –> covalent
2ry –> hydrogen
3ry –> ionic, udrophobic, hydrogen, disulfide
Tetrahydrobiopterin (BH4)?
cofactor used by hydroxylase enzymes in the synthesis of:
- Tyrosine
- Dopamine
- Seretonin
- NO
Methoglobinemia - skin
cyanosis
Methylmalonic acidema?
methylmalonyl-Coa mutase (AR) –> lethargy, vomiting, tachpnea
- -> hyperammonemia, ketotic hypoglycemia, met acidosis
- -> elevated methylmalonic acid + propionic acid
essential fructosuria - alternative pathway for fructose metabolsim
fructose –> fructose 6-P (hexokinase) –> enter glycolysis
Glutamate - glutamine cycle
in the astrocytes: Glutamate + NH3 –> Glutamine (glutamine synthetase)
in neurons: Glutamine –> glutamate (Glutaminase) –> releasing
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
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
acquired obesity - leptin
high leptin –> receptor desensitisation
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))
cyanide poisoning - presentation
reddish skin discoloration, tachypnea, headache, tachycardia, nausea/vomiting, confusion, weaknes –> seirzures + cardiovascular collapse
- lactic acidosis, narrowing of venous arterial PO2 gradient
Hers disease
liver glycogen phosphorylase deficiency –> hypoglycemia, ketosis, hepatomegaly
Spinal muscular atrophy - genes
mutation in Survival motor neuron (SMN1) gene, which encodes a protein involved in assembly of snRNPs in LMN
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
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)
Lynch syndrome - genes (and their function)
mutation of methylation of:
- MSH2 (code MutS) –> detects mismatch
- MLH1 (code MutL) –> after detection –> slides along DNA
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
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
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
Ricin?
from castor oil plant Rinicus commus –> potent toxin that inhibits protein synthesis by cleaving the rRNA component of the eukaryotic 60S subunit
synchronisation of of glycogen degradation with skeletal muscle contraction occurs due to
release of sarcoplasimic calcium releasing –> phosphorylase kinase –> glycogen phosphorylase –> increased glyocogenolysis
liver - ketone using for enegy
cannot because it lacks succinyl coa acetoacetate CoA tranferae (thiophorase) which is required to convert acetoacetate to acetoacetyl coa
