Given scientific fact as input, generate the question from this fact such that it can be answered from the input.

Instead of heat, organisms use catalysis to speed up reactions.
Instead of heat, organisms use what to speed up reactions?

Atp or adenozine triphosphate is used for most energy functions in organisms.
What molecule is used for most energy functions in organisms?

Researchers have identified the receptor proteins for all of the tastes except salty.
Researchers have identified the receptor proteins for all of the tastes except which?