Biochem Flashcards
Base Excision Repair
*glycosylase removes base *Endonuclease cuts 5’ *Lyase cuts 3’ *Polymerase *ligase
Mismatch repair
Mismatch proofread and removed - HNPCC/ Lynch (AD- MST2/MLH1. MUTs, MUTl
Nonhomologous Joining
DS breaks -Ataxia telangectasia Iga Deficiency, Ataxia, course smooth persuit, AFP elevation
BRCA1 and BRCA1
DS DNA repair gene
Stop codons
UGA, UAA, UAG U go away, U are away, U are gone
Enhancers and Silencers
+ and - regulators of transcription close to or far from gene
RNA polymerases
I-rRNA II-mRNA III-tRNA
Bloom syndrome
Helicase mutation - problems with repair and replication - Sunliight hypersensitivity, immunodeficiency, hematologic malignancy, infertility, facial anomalies
End of TRNA for charging
CCA
CDK pairings
Cyclin D/CDK4 - G1->s Cyclin E/CDK2 - G1->s Cyclin A/CDK2 - G2->M Cyclin B/ CDK1 - G2->M
AG- Purine synthesis AA and cofactors
Glycine, glutamine, aspartate TH4 CO2
CUT Pyrimadine synthesis building blocks
Aspartate Carbamoyl phosphate ATP CO2
Pyrimadine synthesis RLS
Carbamoyl phospahate synthetase 2
Urea cycle RLS
Cabamoyl phosphate synthase I
Orotic aciduria
UMP synthase D (AR) *Orotic aciduria, Hypersegmented neutrophils, Glossitis FAILURE TO THRIVE no hyperommonemia Doest respond to B12 or Folate supplementation TX: UMP supplementation
Ribonucleotide reductase
Takes UDP to dUMP *Blocked by Hydroxyurea
Thymidylate synthase
dUMP to dTMP *requires THF *Blocked by 5FU
Dihydrofolate reductase
DHF->TH4 *Necessary for Thymidine synthesis *inhibited by MTX, TMP
PRPP Amidotransferase
RLS in Pyrimidine synthesis Requires THF Inhibited by 6 mercaptopurine Results in IMP
IMP dehydrogenase
IMP-GMP Inhibited by mycophenolate
Xanthine Oxidase
Hypoxanthine —>Xanthine–>Uric acid inhibited by allopurinol/febuxostat
HGPRT
Guanine–>GMP or Hypoxanthine–IMP
Lesch-Nyhan
HGPRT Deficiency *Gout, CNS problems, aggression, self mutilation, choreoform movements TX: Allopurinol
Adenosine deaminase
Adenosine->Inosine (later turned to guanine) Deficient in SCID
SCID
Adenosine Deaminase D B and T cell *Thymic aplasia, candidiasis/PCP, Chronic diarrhea, Failure to thrive
Aminacyl tRNA Synthetase
Attaches AA to tRNA
Autosomal Dominant Diseases
MMOOCHA STAND Marfan/MEN, OI/Osler-weber-rendu, Cholesterolemia, Huntington/vHL, ADPKD/Achondroplasia, Spherocytosis, Tuberous sclerosis, Adenosis polposis, Neurofibromatosis 1/2, Dystrophies myotonic
Autosomal Recessive disorders
ABCDEFGH SPW Albinism/Alpha1AT, Beta thal, CF/CAH, Dubin johnson/deafness, Enzyme Ds(lysosome/glycogen storage), Friedrichs Ataxia/Fanconi, Galactosemia, Hemochromatosis Sickle cell, PKU, Wilsons
X-Linked recessive
Oblivious female will give her boys her X-Linked Disorders Ocular albinism, Fabry, Wiskott-aldrich, G6PD, Hunter syndrome, Brouton agammaglobinemia, Hemophilia AB, Lesch-Nyhan, Duchenne’s MD
Prader willi
Paternal gene chromosome 16 deleted, maternal imprinting silenced *Hypotonia, poor muscle tone, poor feeding, downward mouth, almond eyes *hyperphagia, obesity, short stature, retard, tantrums, ocd, hypogonad hypogonadism, osteoporosis POP: Prader willi, obesity, Paternal gene Dx: FISH Tx: Limit food, rGH
Angelman
Deletion maternal gene chrom 15, paternal imprinted inactivated *Intellectual disability, ataxia, inappropriate laughter MAMA- Maternal Angelman, Mood, Ataxia
Blots
Southern- DNA sample, DNA probe Northern- RNA sample, DNA probe Western- Protein sample, AB probe SW- Protein sample, DNA probe
Indirect Elisa
Colorometric antigen, patient plasma for AB response
Direct elisa
Known antibody- sample for antigen
Nucleotide excision repair
Pyrimidine dimers - Xerodema pigmentosum Bulky changes *Endonuclease *polymerase *ligase
Vimentin
Connective tissue stainable protein
Desmin
Muscle intermediate filament
Cytokeratin
Epithelial Intermediate filament
GFAP
Glial intermediate filament
Neurofilament
Neuron intermediate filament
Alport syndrome
IV collagen DZ Kidney/Ear/Eye BM Persistent microscopic hematuria- episodic gross hematuria
Hereditary hemorrhaghic telangectasia
Telangectasia, epistaxis, AV malformations, GI bleed hematuria Osler-Weber-Randau
Fragile X
v FMRI *intellectual disability * Big balls *Large Jaw *Large everted ears *autism *Mitral prolapse
Friedrichs Ataxia
Mitochondrial defect causing *HYPERTROPHIC CDM *Muscle weakness and hyporeflexia *Vibration/Proprioception *STAGGERING GAIT *falls *nystagmus, dysarthria *Pes Cavis
Edwards syndrome
Trisomy 18 *Intellectual D *Rocker bottom feet *Smal jaw- micrognathia *Low ears *clenched scissorhands *prominant occiput DEATH IN 1 year
PATAU
Trisomy 13 Rocker bottom feet, microphhthalmia, microcphaly. *CLEFT LIP AND PALATE *holoprosencephaly *Polydactyly *Congenital heart disease EARLY DEATH
Williams Syndrome
7 microdeletion- elastin Elfin facies, intellectual D, Hypercalcemia Extremely friendly
Vitamin A
Antioxidant -differentiation of epithelial cells -Adjunct to measels treatment, PML treatment, Acne (isotretinoin Deficiency- Night blindness, dry skin/alopecia, immune D Excess- Pseudotumor cerebri, alopecia and skin changes, Hepatic abnormatities, Cleft palate/Cardiac defects
Thiamine B1
Part of TTP- necessary in many dehydrogenase reactions *Pyuvate/ alpha ketoacid dehydro/Transketolase/ Branched chain keto Deficiency- *Confusion/ophthalmoplegia/ataxia *Confabulation, personality change- Medial thalamus and mamillary bodies *Dry Beriberi- Polyneuritis/muscle wasting *Wet beriberi- High output cardiac failure *** Give thiamine with glucose to hypoglycemic at risk for deficicency**
Riboflavin
FAD- Component of dehydrogenase reactions (TCA cycle) Deficiency- Chelosis, Corneal vasculization, dementia, glossitis
Niacin- B3
NAD factor- can be derived from tryptophan Deficiency- Pellagra *Dermatitis *Dementia *Diarrhea Excess- Facial flushing Hyperglycemia Hyperuricemia
B5 (pantothenate)
CoA part - fatty acid synthesis Deficiency -Dermatitis, enteritis, alopecia, adrenal insufficiency
B6 Pyridoxine
Pyridoxal Phosphate- ALT and AST function VITAL TO PP Transamination, decarbox, glycogenolysis, many neurotransmitters etc Defieciency- *GABA deficiency- Convulsions, hyperirritability, peripheral neuropathy *Can be caused by INH and OCP *Sideroblastic anemia
Biotin B7
Carboxylation enzymes: Pyruvate–>OAA Acetyl CoA->Malonyl CoA Pripionyl CoA –> Methylmalonyl CoA Deficiency: Caused by a ton of raw egg whites or antibiotics *Dermatitis, alopecia, enteritis
Folate B9
Deficiency: Phenytoin, sulfonamides, MTX *Increased cysteine with normal methylmmmalonyc acid
Irreversible enzymes of Gluconeogenesis
Pyruvate carboxylase PEP carboxyKinase F1-6Pase G6Pase
Respiratory burst enzymes
NADPH oxidase- superoxide SOD - SO –> H2O2 Myeloperoxidase H2O2 –> HOCl
Peroxide breakdown in Phagocytes
GSH peroxidase- H2O2-> GSSG and H2O GSH Reductase- GSSG +NADPH –> GSH + NADP G6PD - NADP+ + G6P—> 6PG + NADPH
ApoB48
*Chylomicron Apoprotein at brush border *Needed for liver chylomicron uptake Abberant/missing in Abetalipoproteinemia *Causes failure to thrive *ADEK deficiency *Acanthocytosis *Steatorrhea TX: Vitamin E
LPL
Lipoprotein lipase, uses cofactor CII to remove FFA from lipid particles DEFICIENT IN Type I Hyperlipidemia- Hyperchylomicronemia
APO B100
On VLDL from liver secretion, Binds LDLR
LCAT
Packs cholesterol into HDL Activated by Apo A1
CETP
Transfer of cholesterol esters to VlDL, IDL, LDL
SRB1
Cholesterol scavanger receptor