Specialized Products of AAs and Associated DIsorders Flashcards Preview

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Flashcards in Specialized Products of AAs and Associated DIsorders Deck (19)
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describe the pathway from phenylalanine -> epinephrine


describe Parkinson's disease

  • loss of dopamine producing cells in the basal ganglia
  • characterized by movement disorders; spasticity, tremors, loss of memory, mood disturbance
  • symptoms might be improved by administration of L-DOPA
    • L-DOPA is converted to dopamine in the brain
    • peripheral dopamine formation (in circulation) must be inhibited by administration of a Dopa decarboxylase inhibitor + L-DOPA


what is the dopamine degradation pathway

  • degraded by monoamina oxidase (MAO) and catechol O-methyl (COMT) to produce homovanillic acid (HMA)


what is the degradation pathway of norepi and epi

  • norepi and epi are degraded by MAO and COMT to form vanillyl mandelic acid (VMA)


high urinary VMA and catecholamines are diagnostic of ______

name symptoms of it

high urinary VMA and catecholamines are diagnostic of pheochromocytoma

  • symptoms include: headache, sweating, tachycardia
  • pts have hypertension
  • must use a 24 hour urinary measurement


describe serotonin synthesis pathway and where it is synthesized

  • serotonin is synthesized in the gut, platelets and CNS


describe carcinoid syndrome and what is diagnostic of it

  • tumor of serotonin producing cells in GIT (APUD cells)
  • cutaneous flushing, sweating, and diarrhea
  • bronchospasm
  • increased 5-HIAA in urine


describe the degradation of serotonin


name 3 rxns that require THB

  1. phenylalanine hydroxylase (converts Phe to Tyr)
  2. tyrosine hydroxylase (coverts Tyr to DOPA)
  3. tryptophan hydroxylase (converts Trp to 5-hydroxy tryptophan)


describe PKU II (malignant PKU)

  • deficiency of dihydrobiopterin synthesis or dihydrobiopterin reductase (BH2/BH4)
  • much more severe CNS symptoms
    • decreased neurotransmitter synthesis -- serotonin and the catecholamines (dopamine, norepi, epi)
  • treatment includes dietary Phe restriction and providing dietary biopterin and precursors of the neurotransmitters


describe the defect in the PKU II biochemical pathway


describe GABA synthesis 


describe the synthesis of histamine


describe purpose of creatine

  • reservoir of high energy bonds found in muscle, cardiac, brain
  • synthesized from arginine, glycine and SAM 
  • creatine accepts -P groups from ATP when the muscle is resting
  • creatine donates -P groups to ADP when muscle is contracting
    • acts as a donor to ADP and acceptor to ATP
  • creatine is converted to creatinine
    • spontaneous event
    • end product of creatine metabolism
    • related to amount of muscle mass


describe the creatine metabolism pathway


explain how creatine kinase and creatinine are used as diagnostic indicators

  • levels of creatine kinase (CPK/CK-MB) are a good indicator of myocardial ischemia/damage
  • formation of creatinine is dependent on the muscle mass of an individual
    • muscle atrophy
  • serum creatinine levels are a good indicator of renal function
    • serum creatinine levels rise in acute/chronic renal failure


describe the synthesis of NO and purpose

  • synthesized from arginine by NO synthase in endothelium of blood vessels
  • causes local vasodilation
  • nitroglycerin used in treatment of MI is converted to NO that results in vasodilation of coronary blood vessels and increases blood flow to heart


describe albinism

  • partial or complete deficiency of melanin in the skin, hair and eyes
  • deficiency of the tyrosinase enzyme results in deficient conversion of tyrosine to melanin


describe glutathione

  • glutathione is a tripeptide consisting of glutamate, cysteine and glycine
  • intracellular reducing agent (antioxidant)
  • important for detoxification of toxic hydrogen peroxide (H2O2), especially in RBCs