BioChemistry Flashcards
Boot-shaped heart
RVH, ToF
Continuous machine-like murmur
PDA
Tendon xanthomas
Familial Hypercholesterolnemia
Café-au-lait spots
Neurofibromatosis 1 and 2 & McCune-Albright Syndrome
Tuft of hair on lower back
spina bifida occulta
Classic triad of tuberous sclerosis?
Seizures, angiofibromas, mental retardation
The cell type proliferates during lung damage?
type II pneumocyte
Plummer-Vincent Syndrome is characterized by
Fe-deficient anemia, esophageal web, atrophic glossitis
Symptoms of Plummer-Vincent Syndrome
Anemia + Dysphagia + Beefy-red tongue
Prader-Willi Syndrome Genetics
Imprinting: maternal allele is inactive
Paternal allele has deletion of chromosome 15
Angelman Syndrome Genetics
Imprinting: paternal allele is inactive
Maternal allele has deletion of chromosome 15
Screening Test for HIV
Indirect ELISA (known Ag to test for pt Abs)
Confirmatory Test for HIV
Western blot
Carbamoyl Phosphate Synthetase 1 - Pathway
Urea Cycle
Carbamoyl Phosphate Synthetase 1 - Location
Mitochondria
Carbamoyl Phosphate Synthetase 1 - N Source
Ammonia
Carbamoyl Phosphate Synthetase 2 - Pathway
Pyrimidine Synthesis (Rate limiting step)
Carbamoyl Phosphate Synthetase 2 - Location
Cytosol
Carbamoyl Phosphate Synthetase 2 - N Source
Glutamine
Nucleosome core is composed of
2 - H2A
2- H2B
2 - H3
2 - H4
Nucleosome core is (+) charge d/t
arginine & lysine residues
Function of Histone H1
stabilize nucleosome/DNA (linker histone)
Heterochromatin
tightly packed
Euchromatin
loosely packed
DNA methylation at CpG islands results in
repressed transcription
Histone methylation results in
repressed transcription mainly
Histone acetylation results in
active transcription
Purines
A, G
Pyrimidines
C, U, T
Deamination of cytosine results in
uracil
Which nucleotide pair has a higher melting temp?
G & C -> 3 hydrogen bonds
A & T have 2 H bonds
Purine synthesis requires which amino acids
Glycine, Aspartate, Glutamine
UMP Synthase
Orotic Acid + PRPP —->UMP
CPS-II
CO2 + Glutamine —-> Carbamoyl Phosphate
Ribonucleotide Reductase
UDP —-> dUDP
Thimidylate Synthase
dUMP ——> dTMP
What molecule is necessary for the production of Thymine?
Tetrahydrofolate
Dihydrofolate Reductase
Dihydrofolate —-> Tetrahydrofolate
Glutamine PRPP Amidotransferase
PRPP —-> IMP
IMP Dehydrogenase
IMP —–> GMP
Deficient UMP Synthetase
Orotic Aciduria
Pyrimidine synthesis requires which amino acids
glutamine, aspartate
Orotic Aciduria S/S
Orotic aciduria, megaloblastic anemia, normal ammonia levels
Tx for Orotic Aciduria
Supplement w/ Uridine
orotic aciduria + HYPERammonemia
Ornithine Transcarbamylase deficiency
Most common cause of Megaloblastic anemia?
Vit B12 or folate deficiency
Xanthine Oxidase
Xanthine & Hypoxanthine —-> Uric acid
What enzyme recycles Guanine or Hypoxanthine ——–> GMP or IMP?
HGPRT
What disease results from the absence of HGPRT?
Lesch-Nyhan Syndrome
Lesch-Nyhan Syndrome S/S
gout, aggressive behavior, low IQ, self-mutilation (lip biting), movement disorder (dystonia)
Lesch-Nyhan Syndrome Genetics
X-linked
Lesch-Nyhan Syndrome Tx
Allopurinol or Febuxostat
Orotic Aciduria Genetics
AR
Primosome
DNA Helicase + Primase Complex
Nonsense mutation
signals a stop codon (UAA, UAG, UGA)
Mismatch Repair
cut daughter strand & remove segment containing mismatched base
Nucleotide Excision Repair
Damage that occurs sometime after DNA replication (UV light –> thymidine dimer); excise base, remove damaged segment
Hereditary Nonpolyposis Colorectal Cancer - defective
mismatch repair
Xeroderma Pigmentosum - defective
nucleotide excision repair
Bloom Syndrome - defective
helicase, affecting DNA replication & repair
Ataxia Telangiectasia - defective
double-stranded DNA break repair
Adenosine Deaminase deficiency
causes Severe Combined Immunodeficiency (SCID)
BRCA-1/-2 - defective
double-stranded DNA break repair
Crest Scleroderma
anti-centromere Ab
Diffuse Scleroderma
anti-scl70 inhibiting topoisomerase
lac operon produces what enzyme
b-galactosidase
What 2 proteins regulate the lac operon?
CAP & lac repressor protein
What 2 conditions allow for activation of the lac operon
excess lactose, absent glucose
Hairpin loop
termination site of RNA transcription characterized by GC rich segment followed by uracil rich
Termination of RNA transcription in prokaryotes?
rho factor or hairpin loop
aminoacyl tRNA synthetase
A.A. + tRNA —-> aminoacyl tRNA (on 3’)
peptidyltransferase
(23S ribozyme) transfers tRNA from A site to P site
IF-2
binds 30S subunit & causes Met-aminoacyl tRNA to bind —-> initiating translation
EF-G (prokaryotes) EF-2 (eukaryotes)
translocation for growing a.a. chain
Post-translational modifications
trimmed, glycosylation, hydroxylation, disulfide linkages, etc
Diptheria toxin & Exotoxin A inhibit
EF-2
Genetics Achondroplasia
AD
Genetics FAP
AD
Genetics Familial Hypercholesterolemia
AD
Genetics Osler-Weber-Rendu Syndrome
AD
Genetics Hereditary Spherocytosis
AD
Genetics Huntington Disease
AD
Genetics Marfan Syndrome
AD
Genetics MEN
AD
Genetics Neurofibromatosis-1/-2
AD
Genetics Tuberous Sclerosis
AD
Genetics Von-Hippel-Lindau Disease
AD
Genetics Leber hereditary optic neuropathy
Mitochondrial Inheritance
Leigh Syndrome (subacute sclerosing encephalopathy)
Mitochondrial Inheritance
Hardy Weinberg Equation
p + q = 1 p^2 + 2pq + q^2 = 1
Anticipation
age of onset or worsening of disease occurs over successive generations (d/t trinucleotide repeats)
Incomplete Penetrance
not all mutant genotypes will display phenotype
What is an example of pleiotropy?
PKU (1 gene has multiple phenotypic effects)
Example of locus heterogeneity?
Marfan (many genes may result in same phenotype)
Example of imprinting?
Prader-Willi & Angelman Syndrome
Genetics of Ocular Albinism
X-linked Recessive
Genetics of Albinism
AR
Genetics of Fabry Disease
X-linked Recessive
Genetics of Cystic Fibrosis
AR
Genetics of Glycogen Storage Disease
AR
Genetics of Hemochromatosis
AR
Genetics of Wiskott Aldrich
X-linked Recessive
Genetics of G6PD deficiency
X-linked Recessive
Genetics of Hunter Syndrome
X-linked Recessive
Genetics of Bruton Agammaglobulinemia
X-linked Recessive
Genetics of Mucopolysaccharidosis
AR
Genetics of PKU
AR
Genetics of Sickle Cell
AR
Genetics of Sphingolipidosis
AR
Genetics of Hemophilia A/B
X-linked Recessive
Genetics of Thalassemias
AR
Genetics of Lesch-Nyhan Syndrome
X-linked Recessive
Genetics of Duchenne Muscular Dystrophy
X-linked Recessive
Most common cause of Lysosomal Storage Disease?
Gaucher Disease
Southern Blot
DNA
Northern Blot
RNA
Indirect ELISA
Known Ag, pt Ab
Ataxia telangiectasia - deficient
non homologous end joining
Duchenne Muscular Dystrophy - mutation type?
frameshift
Sickle Cell Disease - mutation type?
missense
Promoter sequence
TATA & CAAT upstream (RNA pol & TFs bind)
RNA pol I
makes rRNA (most abundant)
RNA pol II
makes mRNA (largest)
RNA pol III
makes tRNA (smallest)
alpha-amanitin MOA
poison inhibits RNA pol II —> hepatotoxicity
Modifications hnRNA —–> mRNA
- 7-methylguanosine cap on 5’
- Polyadenylation tail 3’
- Splicing
snRNPs
bind to hnRNA to form a spliceosome —> lariat-shape —> removal of intron (splicing)
anti-SMITH Abs
antibodies to spliceosomal snRNPs are specific for SLE
anti-U1 RNP Abs
specific for mixed connective tissue disease
Abnormal splicing
abnormal variation to alternative splicing (oncogenesis, b-thalassemia)
tRNA 3’ Acceptor stem
binds a.a., sequence is CCA
T arm of tRNA
(thymine, pseudouridine, cytosine) tRNA-ribosome binding
D arm of tRNA
(dihydrouracil) tRNA- aminoacyl tRNA synthetase
Degeneracy of the genetic code
3rd wobble position may code for same tRNA/a.a.
Post-translational modifications
Trimming of N- or C-terminal pro peptides from zymogen, folding, methylation, phosphorylation, glycosylation, hydroxylation, etc
Chaperone protein
facilitates/maintains protein folding (heat-shock protein in yeast prevents denaturing at high temps)