Question

14. Which mechanism is responsible for glucuronidation? a. Ei b. SN c. E2 d. SN2 e. None of the above 15. Mathematically what is the Kow? 16. What does the Kow tell about a compound? 17. What cofactor is required for methyltransferase? a. Glucuronic acid b. S-Adenosyl methionine c. Acetic acid d. Sulfate e. Acetyl COA 18. When is radiation possibly good for us (one of two possible)? 19. Why would gel electrophoresis cell analysis be important in toxin research? 20. What happens after exposure and uptake of a toxin?

Answer 1

The correct answers are as follows:

1. Sn2: glucuronidation reaction is a bi substrate reaction catalyzed by UDP-glucuronosyltransferases (UGT) which utilizes a direct SN2-like mechanism.
2. Bioconcentration (BCF) is defined as the accumulation of a chemical with in or upon on an organism when the source of chemical is solely water, a term very useful for aquatic toxicity and is expressed as
   BCF = (conc. in biota/ conc. In water)
   n-Octanol/Water Partition Coefficient or Kow is defined as the ratio of the conc. of a chemical in n-octanol and water at equilibrium (at a specified temperature).
   i.e. Kow = Concentration in Octanol/ Concentration in water
   Bcf can be expressed in terms of logKow as
   BCF = mLogKow + b
3. Log (Kow) is the parameter for the expression probability of distribution of different substances in different environmental compartments. Compounds with high logKow values (i.e. >4.5) poses a threat as they have the potential to bio-concentrate because are readily absorbed to organic matter in soils or sediments due to their low affinity for water.
4. The co factor as well as the methyl group donor for methyl transferase is SAM (s adenosyl methionine).
5. Radiation can be good for us if it is used for:
   a. microbcidial / bacteriocidal and sterilization
   b. Anti cancer
6. Gel electrophoresis can be used to measure and identify the Different RNA content of the toxin treated cell vs normal to identify the metabolic pathway it upregulates or down regulates
7. After exposure to a toxin , the cell absorbs the toxin and the toxin binds to its designated target and creates a metabolic imbalance so that the cell ultimately lose its capability to function and die.