I followed this list to answer question 1 and 2 of the worksheets.

1. Is the chemical bioavailable?

• Is its solubility in H₂O sufficient?
• Are sorptive properties negligible?
• Does molecular size and polarity allow up take of the molecule?

2. Are there bonds that can be subject to spontaneous or enzymatic hydrolysis?

3. Is there an accumulation of structural elements (substituents) that make initial or further biodegradation unlikely (e.g. vic. CH₃-substitution, perfluoroalkyl residues)?

4.Does the redox-potential allow the attack of electrophiles such as activated O-species?

5. Is a nucleophilic reductive transformation more likely than electrophilic one?

5a. Can reductive transformation lower the redox potential so that subsequent oxidative catabolism is reasonable?

6. Are there structural elements that allow oxygenations (aromatic/aliphatic vic-OH) or oxidation plus decarboxylation?

7. Can xenobiotic structural elements be subject to oxygenolytic elimination?

8. If the answer to 2, 4, 5, 5a, 6, and 7 is "yes", do these transformations increase biodegradability?

8a. Can further transformations such as those asked in 6. and 7. yield metabolites, that are subject to general metabolic reactions and are finally funneled into the central metabolic cycles?

9. If the answer to 8 is "no".

• Are dead end metabolites formed? Is metabolic misrouting a problem?
• Are highly reactive suicide metabolites formed (Is co-metabolism counterproductive)?
• Can metabolites be subject to chemical misrouting (oxidative coupling, polymerization)?
• Can metabolites be subject to strong physisorption? (Question 1. to metabolites)