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Biochemistry

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drnieves's version from 2017-06-21 13:44

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Question Answer
MCAD deficiencyAR. From fatty acid oxidation.
MCAD DeficiencyDecreased ability to break down FA into acetyl CoA. Accumulates 8-10 C fatty acyl carnitines
MCAD deficiency sxHypoketotic hypoglycemia. Vomiting, ethargy, seizures, come, liver dysfunction.
MCAD deficiency txAvoid fasting
MCAD deficiency enzymeAcyl Coa dehydrogenases (medium chain acyl cos dehydrogenase.
FA synthesisTransport of citrate from mitochondria to cytosol. In liver, mammary glands, and adipose tissue.
1ry carnitine deficiencyInherited defect in transport of LCFAs into mitochondria. Weakness, hypotonia, and hypoketotic hypoglycemia.
Oxaloacetate depleted for gluconeogenesisProlonged starvation and diabetic ketoacidosis.
Excess NADH shunts oxaloacetate to malate.Alcoholism
Low oxaloacetate and excess NADH causesBuildup of acetyl cos, which shunts glucose and FFA toward the production of ketone bodies
Purine salvage deficienciesAdenosine deaminase, Lesch nyhan syndrome
Adenosine deaminase deficiencyCause of AR SCID
Excess ATP and dATP imbalances nucleotide pool.. There is no inhibition of ribonucleotide reductase= No DNA synthesis= decrease lymphocyte countAdenosine deaminase deficiency
Lesch nyhan syndromeXR. No HGPRT (hypoxanthine to IMP and guanine to GMP. Excess uric acid and de novo purine synthesis.
HGPRT- Hyperuricemia, gout, pissed off, retarded, dystoniaLesch nyhan syndrome
Lesch Nyhan txAllopurinol or febuxostat
TelomeraseRNA dependent DNA polymerase. Adds in the 3' ends to avoid loss of material. Eukaryotes only. Epidermal basal cells.
Muscular dystrophiesDuchenne, Beker, Myotonic type 1, Fragile X
DuchenneX linked. Frameshift mutation causing truncated dystrophin protein (DMD gene) that inhibits muscle regeneration.
Pseudo hypertrophy of calf muscles (fibrofatty replacement of muscle)Duchenne
CC of death in DuchenneDilated cardiomyopathy.
Dystrophin proteinConnects the intracellular cytoskeleton (actin) to the transmembrane proteins a and B dystroglycan, which are connected to ECM. Loss= myonecrosis.
Duchenne labsIncrease in CPK and aldolase. Western and biopsy to confirm.
BeckerX liinked. Due to a non frameshift insertions. Partially functional protein.
Myotonic type 1AD. CTG trinucleotide repeat expansion in the DMPK gene leading to abnormal expression of myotonic protein kinase.
Myotonic type 1 sxMyotonia, muscle wasting, cataracts, testicular atrophy, frontal balding, arrhythmia.
Fragile XX linked. Affects methylation and expression of FMR1 gene.
Second MCC of intellectual disabilityFragile X
Fragile XTrinucleotide repeat disorder. CGG
Macroorchidism, lrge jaw, large everted ears, autism, mitral valve prolapseFragile X sx
Friedrich ataxiaGAA
HuntingtonCAG
Myotinic dystrophyCTG
From headache and dizziness to convulsions and respiratory arrestCO poisoning sx
CO poisoning MOAcompetitively bind iron present in heme proteins with higher affinity than O2= carboxyhemoglobin. Remaining 3 heme groups have increased affinity to O2 (leftward shift). Can bind cardiac myoglobin.
Binds to cytochrome oxidase, inhibiting aerobic metabolism and exacerbating tissue hypoxiaCO
High flow or hyperbaric O2CO poisoning tx.
Inhibits complex 4Cyanide and CO
Disorders of galactose metabolismgalactokinase deficiency and classic galactosemia
Galactokinase deficiencyAR. Galacticol accumulation. Infantile cataracts. Galactose in urine and blood. Cant tract object and don't have social smile.
Classic galactosemiaAR. Absent galactose-1-phosphate uridyltransferase. Galacticol accumulates.
Failure to thrive, jaundice, hepatomegaly, infantile cataracts, intellectual disability. E. Coli sepsis in neonatesClassic galactosemia sx
Classic galactosemia txExclude galactose and lactose.
Alkaptonuria (ochronocisis)AR. No homogentisate oxidase. Tyrosine to fumarate pathway.
Homogentesic acid (black ) accumulates in tissueAlkaptonuria sx.
Polyol pathwayIn hyperglycaemic states, alludes reductase converts glucose to sorbitol at a rate faster than it can be metabolised. Sorbitol accumulates leading to influx of water= osmotic cellular injury. Depletion of NADPH by aldose reductase increases oxidative stress, which accelerates development of cataracts and diabetic microvascular complications.
snRNAsynthesised by RNA polymerase II in nucleus and complexes with specific proteins to form snRNPs.
snRNPscomponent of spliceosomes, which remove introns from pre-mRNA.
SLEautoab against snRNPs (anti smith)
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Question Answer
Lac operonexample of polycistronic mRNA. Codes for proteins of lactose metabolism by E. coli. Transcription and translation of these bacterial proteins is regulated by a single promoter, operator, and regulatory elements.
SplicingBy spliceosomes. Remove introns containing GU at 5' and AG at 3'. Cant remove introns= dysfunctional protein.
HbS sicklinganoxia (low pH and high 2,3-BPG.
HyperammonemiaExcess NH4 that depletes a-ketogluterate= inhibition of TCA.
Hyperammonemia txLimit protein. Lactulose to acidify GI and trap it. Rifaximin to decrease colonic ammoniagenic bacteria. Benzoate or phenylbutyrate.
Ammonia intoxicationTremor, slurring of speech, somnolence, vomiting, cerebral deem, blurring of vision.
Hepatic encephalopathycauses bleeding of GI= increase N resorption= increase ammonia.
Astrocytes take ammonia and glutamate and make glutamine with glutamine synthetase. Glutamine released and taken by neurons and converted to glutamatecycle glutamate- glutamine.
Excess ammoniaincreasing glutamine= swelling.
rt-pcrmRNA
DNA polymerase 15'to 3' exonuclease activity in addition to 5' to 3' polymerase and 3' to 5' exonuclease activities. Functions to remove primer and repair.
Chronic hemolysis, increase in bile recyclingblack gallstones
Infection= B-glucoronidasesbrown gallstones.
TransketolaseNon oxidative part of pentose phosphate pathway that converts ribose 5- phosphate to fructose 6 phosphate.C
Cori disease (III)Debranching enzyme deficiency (a-1,6- glycosidese). AR.
Glycogen storage diseaseVon Gierke, Pompe, Cori, McArdle
Alaninebefore converting it to glucose, its amino acid is passed to a-ketogluterate.
tRNA structure3' has ACC and OH group. 5' has phosphate. D loop + T loop + anticodon loop.
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