Question

What kind of biological molecule speeds up chemical reactions and decreases activation energy?

Answer 1

You speak of a `"catalyst........."`, i.e. here `"an enzyme"`.......

Explanation:

Catalysts work by altering the activaton energy of a reaction; they can accelerate or inhibit. Catalysts can do nothing to alter the thermodynamics of a reaction.

Biological systems are extensively catalyzed by enzymatic catalysts.