TMPD and DMPD can be used to test if an organism possesses an enzyme that reduces this compound, which helps identify if non-lactose-fermenting gram negative rods are pseudomonas. Requirements for this molecule can be approximated by growing an organism in thioglycolate broth. A lack of access to this molecule may have led to the evolution of the hydrogenosome. Organisms that (*) tolerate this molecule detoxify its reactive byproducts using SOD and (10[1])catalase, thus avoiding (-5[1])a namesake (-5[1])form of stress. (-5[1])Organisms which do not metabolize this molecule either use alternative electron acceptors for respiration or fermentation to generate ATP. (10[1])For 10 points, (10[1])obligate anaerobes (10[1])cannot tolerate atmospheric (10[1])concentrations of what gaseous molecule? (10[1])■END■ (10[2])