What effect does extreme temperature and extreme ph have on enzyme activity?

it speeds up enzyme activity.
it slows down enzyme activity.
it stops enzyme activity.
it has no effect on enzyme activity.

Well, if the temperature reading or value and the pH value are on the extreme ends, past optimal, and even past the tolerable levels for enzyme to function it would most likely stop enzymatic activity, as the enzyme would probably be denatured lose its shape due to very high conditions, thus incapable of catalyzing the said reaction.

Ba1.   a2. c3. d4. b5. b6. c7.   c8. d