Does temperature have more of an effect on the cell membrane or the concentration of solvents such as methanol and acetone?

Answer 1

The best answer is "it depends." It would be helpful to know the context in which you are asking. Is this a general question, or something specific? For example, what are the concentrations of methanol and acetone? What temperature are you considering?

In general, if any chemical, not just methanol or acetone, is in a high enough concentration then it could be harmful. For example, breathing 100% Oxygen for a long time is definitely harmful, but we breathe it at 20% concentrations every day.

For the most part, when cells that are in petri dishes are exposed to these solvents, these chemicals would likely be harmful. That's one reason why cells team up and form tissues - there is protection to be had in numbers!