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Beta 0 Thalassemia
"Cooley's Anemia"No production of Beta chainsOnly produce HbA2 and HbF and unstable alpha4 tetramersTetramers trash the RBCs in marrow -> life-threatening anemia TERM 2
Beta+ Thalassemia
DEFINITION 2 "Thalassemia Minor"Has only 1 copy of the normal beta-globin geneHas genetic trait; usually no health problems or mild anemiaDecrease in Beta chain synthesis, net decrease synthesis of HbA(micocytic anemia - less HbA)Remaining alpha chains precipitate, react with cell membranes, interfere with cell divisionAct as foreign bodies, lead to destruction of RBCs TERM 3
Alpha Thalassemia
DEFINITION 3 Most common monogenic gene disorder in the world(Hemoglobin Bart hydrops fetalis - more severe type)HbH disease - milder form TERM 4
Hb Bart
DEFINITION 4 No alpha globin is synthesized, results from loss and inactivation of all 4 alpha allelesFetuses unable to deliver O to tissues, relatively unstable; normally succumb to severe fetal hypoxia TERM 5
Hemoglobin H Disease
DEFINITION 5 Caused by loss of 3/4 alpha globin allelesShortage of alpha globin prevents cells from making normal HbResults in hemoglobin H (Beta globin tetramers)Characterized by a high Beta globin to alpha globin synthesis ratio
Sickle Cell Disease
Mutation in Beta globin gene of Hb -> changes 6th AA (Glutamic Acid -> Valine)"HbS"Repeated cycles of oxygenation and deox -> irreversible sickling -> cloggingValine - hydrophobic and outside of tetramer and acts as a sticky patch to attach to another Hb molecule via phenylalanine and leucineTends to form long fibers of blood TERM 7
Sickle / Beta Thalassemia
DEFINITION 7 Inherit 1 gene for HbS f/ 1 parent and 1 for Beta Thalassemia f/otherSeverity determined by quantity of normal Hb produced by Beta ThalHbSB0 - gene produces no normal Hb, B0 Thal (identical to sickle)HbSB+ - some produce small amount of normal Hb (B+ Thal)Shows no hemoglobin A when electrophoresis (depends on amount by HbB+) TERM 8
Sickle / Malaria
DEFINITION 8 Sickle cell provides resistance against malarial parasite (which lives in RBC)1) Sickled cells sent to spleen for destruction (not enough time for parasite life cycle)2) Parasite thrives on Hb mutated and polymerized Hb cannot be ingested by parasite3) Sickle cells sickle when decr. O2. Parasites use up O2 and cell sickles4) Cell membrane stretched and leaks nutrients needed by parasite TERM 9
Hemozoin
DEFINITION 9 Digestion of hemoglobin -> release of Heme (toxic) -> destabilize and lyse membranesDetoxify by polymerize Heme -> HemozoinChloroquine - interferes with this conversion TERM 10
Hemoglobin C
DEFINITION 10 Mutation at codon 6 (glutamic acid -> Lysine) in Beta globinforms crystals and impairs malariaMild hemolytic anemia when homozygotic
Creutzfeld-Jakob Disease
Human Prion disease -> progressive dementia (~60yo)Diagnosis only by brain biopsy/autoposyiCJD (iatrogenic) - done by exposure of brain/nervous tissue from medical procedures (ex: injected human growth hormone)fCJD (familial) - Dominantly inherited trait, Heterozygotes developsCJD (sporadic) - Spontaneous mutation on the PrP genevCJD (variant) - Each has a particular genetic profile; strong evidence that break out f/BSE (mad cow) TERM 17
Gerstmann-Streussler-Scheinker Disease
DEFINITION 17 Early stages - varying levels of ataxia (lack of muscle coordination)Prion disease from inheritance of PRNP geneP102L and A117VCan transmit disease to other species TERM 18
Fetal Familial Insomnia (FFI)
DEFINITION 18 Adults >50yo w/progressive sleep disorder -> death within a yearInherit a PRNP gene w/ D178NCan transmit to transgenic mice TERM 19
Animal Prion Disease Scrapie
DEFINITION 19 Spongiform encephalopathy of sheep (progressive loss of motor control)Animals tendency to rub against things (rub skin raw -> scrape) TERM 20
Mad Cow Disease
DEFINITION 20 Bovine Spongiform EncepohalopathyProgressive loss of motor controlTransmissible, long incubation timeInfection linked to meat+bonemeal (f/new extraction technique)
Alzheimer's Disease
Memory loss, dementia, impairment in cognition and behaviorLate onset or sporadic ADApoE4 - risk factor geneAmyloid plaques - contain large amounts of Beta-amyloid AB42Beta amyloid - initial cause -> neurofibrillary tangles; fragments snipped f/amyloid precursor protein (APP); plaques in hippocampusAPP can be processed by alpha, beta, gamma secretasesAB protein generated by successive actions of B and G secretasesG secretases - produces C-terminal end of ABAB42 - more likely to form plaques and more toxic; fibrillogenic TERM 22
Alzheimer's Disease and factors
DEFINITION 22 Down's syndrome: Increases risk of AD because APP is on chromosome 21Tau Protein: stabilize microtubules normally. In AD, begins to pair with other Tau and get tangled up -> MTs crumble; phosphorylated in AD by GSK3; contributes to neurofibrillary tangleHigh Cholesterol: Statins - choletsterol lowering drug decreases risk of AD; lipid raft needed for gamma secretase to cutApoE4 : removes excess cholesterol f/blood (if normal ApoE);; at risk, binds to Ab more readily and increased production of AB TERM 23
Parkinson's Disease
DEFINITION 23 syncnucleinopathy due to accumulation of alpha synuclein in the form of Lewy BodiesDementia has many similarities TERM 24
Huntington's Disease
DEFINITION 24 Progressive loss of neurological functionHereditary neurodegenerative disease known as 'poly Q disease'Results from expansions of CAG of huntingtin gene (Glutamine); susceptible to misfolding and aggregationAltered form - mH++ -> increases decay rate of certain neurons
