Urea Cycle S2M2

  1. Overeating animal protein can have what adverse effects on the body
    Strain on the liver, kidney, and cause gout
  2. In what ways is Nitrogen lost from the body
    • Urine
    • Feces
    • Milk (lactation)
    • Other loses
  3. What are the Essential amino acids
    • Arginine
    • Histidine
    • Isoleucine
    • Leucine
    • Lysine
    • Methionine
    • Phenylalanine
    • Threonine
    • Tryptophan
    • Valine
    • "MATT is the VP on the HILL"
  4. What is the most important route for removing nitrogen from the body
  5. What is the most important entry of Nitrogen into the body
    Protein intake
  6. All amino acids are broken down to what amino acid early on
  7. What are the first two reactions of the Urea cycle, and where do they take place
    • Carboxymoylphosphate synthase I
    • Ornithine transcarbamoylase
    • Occurs in the mitochondria of the liver
  8. What allosteric activator does Carbomoylphosphate synthetase I require
  9. What is the first step and products for the catabolism of most amino acids
    Transaminase forming alpha-ketoacid and glutamate
  10. What amino acids don't undergo transaminase
    Lysine and Threonine
  11. All transaminase reactions in glutamate formation require what coenzyme
    Pyridoxal phosphate (Vit B6)
  12. What are the two most important enzymes used for transaminase of amino acids making Glutamate
    • Alanine aminotransferase (ALT)
    • Aspartate aminotransferase (AST)
  13. What coenzymes does Glutamate dehydrogenase use
    • NAD+
    • NADP+
  14. NAD+ and NADP+ are used for what pathways in regard to glutamate dehydrogenase
    • NADP+ Anabolic pathways
    • NAD+ Catabolic pathways
  15. alpha-ketoglutarate is significant how
    It is one of the products of Glutamate dehydrogenase and is an important marker in the blood when there is severe liver damage
  16. What are the products of Glutamate dehydrogenase
    • alpha-Ketoglutarate
    • Ammonia (NH3)
  17. What are the regulators of Glutamate dehydrogenase
    • Guanosine triphosphate (inhibitor)
    • ADP (activator)
  18. What is the importance of D-amino acids in the body
    They are found in bacteria cell walls and plants and are used by the body in the brain. Astrocyte production, as well as playing a role in long term potentiation, and Glutamate exitotoxicity
  19. What pharmaceutial use do D-amino acids have
    Treatment for Schizophrenia
  20. Urea is produced where
    In the liver and is then transferred to the kidney via the blood for excretion
  21. Exitotoxicity
    • Damage to nerve cells as a result of over stimulation by neurotransmitters like glutamate
    • Can be a result of high D-amino acids
  22. Why is ammonia toxic
    It collects in lysosome's and neutralizes them damaging their function of breaking down waste materials
  23. What substrates are required for Carbamoylphosphate synthase I
    • NH3
    • CO2
    • 2ATP
    • H2O
  24. What are the products of Carbamoylphosphate synthase I
    • 2 ADP
    • Phosphate
    • 3H+
    • Carbanoyl phosphate
  25. Ornithine transcarbamoylase uses what substrates to make L-Citrulline
    • Ornithine
    • Carbamoyl phosphate
  26. What steps of the Urea cycle take place in the liver cytosol
    • Argininosuccinate synthetase
    • Argininosuccinate lyase
    • Arginase
  27. Argininosuccinate synthetase uses what substrates and makes what products
    Uses Citrulline, ATP, and Aspartate to produce Argininosuccinate, AMP, and 2 phosphates
  28. Argininosuccinate lyase uses what substrates and makes what products
    Uses Argininosuccinate to make L-Arginine and Fumarate
  29. Arginase uses what substrate to make what products
    H2O and Arginine to make Ornithine and Urea
  30. What is the result of a Urea cycle failure
    Hyperammonemia and encephalopathy (disease of the brain)
  31. What is the treatment of Urea cycle failure
    Alcohol free and reduced protein diet replacing essential amino acids with their alpha-ketoacids
  32. What is the rate limiting step of the Urea cycle
    Carbamoylphosphate synthetase I
  33. What is the activator of Carbamoylphosphate sythetase I
    N-Acetyl glutamate
  34. Glutamine
    An amide of glutamic acid that provides a nontoxic storage and transport for ammonia
  35. What are the normal levels of ammonia in the blood
    5-50 µmol/L
  36. What are some physical findings in someone that is suffering from hyperammonemia
    • Tremors
    • Slurred speech
    • Vomiting
    • Blurred vision
    • Coma
    • Failure to feed (babies)
  37. Orithine transcarbamoylase deficiency
    • X-linked (effects mostly males)
    • Most common inherited hyperammonemia
  38. Glutaminase and Glutamate dehydrogenase form
    NH3 (Ammonia)
  39. Lysinuric protein intolerance
    • Defective transporter for basic amino acids
    • Results in reduced absorption of Lys and Arg
    • Results in partial Urea cycle failure
  40. Cystinuria
    • Lys, Arg, Ornithine, and Cystine defect
    • Failure of Cystine reuptake in the kidney leading to kidney stones
Card Set
Urea Cycle S2M2