Shared Flashcard Set

Details

Respiratory System
TCA Cycle
5
Medical
Graduate
11/24/2012

Additional Medical Flashcards

 


 

Cards

Term
Treatment for PDH deficiency
Definition
  • Ketogenic diet- high fat, low carbs
  • Dicholoacetate- blocks enzyme that phosphorylates PDH, thus inactivating it. Therefore, DCA keeps PDH active
Term
Dietary thiamine deficiency
Definition
  • Cofactor for E1 of PDH (which decarboxylates pyruvate)
  • Can lead to Berberi or Wernicke-Korsakoff syndrome (in alcoholics)
    • Neurological and cardiovascular disorder often seen in malnurished individuals
    • *Unable to oxidize pyruvate
    • Organs, like brain, that heavily depend on aerobic oxidation of glucose are affected
    • *Elevated levels of pyruvate, alanine, and lactate often seen in blood
Term
Neuropsychiatric Syndromes resulting form thiamine deficiency
Definition

Wernicke's encephalopathy

  • Triad of opthalmoplegia:
    • Weakness or paralysis or eye
    • Ataxia- unbalanved
    • Sudden confusion
  • *Nystagmus- rapid involuntary eye movements

Korsakoff psychosis

  • Persistent deficits in learning and memory
    • Amnesia: Anterograde (rapidly forget new info) and Retrograde (forget old info)
    • Confabulation- unable to recall what really happened, while making up plausible stories, without being aware of doing so
  • Wernicke-Korsakoff syndrome when occurs in conjection with Wernicke's encephalopathy
    • Hemorrhages are classic signs

Medical emergencies

  • *IV thiamine must be given BEFORE IV glucose 
  • Also seen in extended vommitting, thiamine deficiency, and systemic diseases like HIV, cancer, uremia with hemodialysis
Term
Allosteric and covalent regulation of PDH complex
Definition

Turned off when energy is high and turned on when energy is low- you don't need more energy if you have a lot


Allosteric

  • Activation: low energy molecules
    • Long chain FA, NADH, acetyl-COA, ATP
  • Inhibition: high energy molecules
    • AMP, CoA, NAD+

Phosphorylation

  • Protein kinase- inactivates E1
    • Inhibited by high levels of ATP
  • Phosphoprotein phasphatase- active E1
    • Stimulated by Ca2+

 

 

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