Toxicology Exam 1

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Toxicology Exam 1
2011-01-21 17:22:43
Dr Badr\'s lecture

Dr. Badr's lecture 1/19
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  1. study to identify the specific target molecule which is attacked by a toxin
    molecular mechanisms
  2. Toxins may be
    specific and non-specific
  3. Example of a non-specific toxin
    sulfuric acid
  4. Direct effect
    attack molecule of the retina resulting in blindness
  5. Indirect effect
    attack the pancrease resulting in diabetes
  6. Direct targets of toxins
    • Proteins
    • Lipids
    • Nucleic Acids
  7. Proteins that may be targeted by toxins
    • Enzymes
    • Receptors/Ion Channels
    • Transport Proteins
  8. Enzymes that may be targeted by toxins
    • Acetylcholine esterase
    • Mitochondrial enzymes
  9. Organophosphates
    • methylparoxon
    • ties up ACHE
  10. Example of enzyme aging
    ACHE-Phosphate loses a methyl group resuling in a fre --O
  11. Three types of chemicals to help enzyme recovery
    • Hydroxylamine
    • Hydroxamic acid derivatives
    • Oximes
    • (all contain N-OH group)
  12. Oximes
    • Pralidoxime (2-PAM)
    • more efficient than water to recover ACHE
  13. Mitochondrial enzymes that may be targeted by toxins
    • Cytochrome oxidase
    • ATPase
  14. Complex I of the respiratory chain deals with
    NADH - linked molecules
  15. Complex II of the mitochondrial respiratory chain deals with
    FADH linked molecules
  16. Inhibitor of Complex I (NADH complex)
  17. Amytal
    barbituric acid derivative
  18. Oligomycin
    inhibitor of ATPase
  19. Cyanide
    inhibitor of cytochrome oxidase complex
  20. Tetrodotoxin
    sodium channel inhibitor
  21. Effects of toxins on receptors/ion channels
    • increased or decreased ions moving through the channels
    • intracellular enzyme activity increased or reduced
    • gene expression may be altered
  22. Most abundant protein carrier in the body is
    • hemoglobin
    • carries oxygen
  23. Oxidized form of iron
  24. reduced form of iron
  25. CO binds heme ____x better than O
  26. Oxidized iron in hemoglobin is called
    • methemoglobin
    • will not bind oxygen
    • can sometimes be beneficial