Once there is enough oxygen, I would think that the pyruvate could be used for oxidative phosphorylation.

Thank you for your insightful answers! I do agree with @rotaredom that if there is melting of stemloops (@tyersome) and other "tertiary" DNA structures within the ssDNA, then this denaturation should also be cooperative, and should follow a similar sigmoidal curve to the dsDNA shown... The paper on hydrolysis (@rotaredom) would mean that there's also single nucleotides, which absorb more. It would make sense in this case if the rate of hydrolysis increases linearly with temperature, as shown in the graph. I'm curious for other interpretations!