Enzymes act as catalysts because

a: they raise the activation energy

b: they lower the activation energy

c: they use activation energy

d: they maintain activation energy

B.) they lower the activation energy.

Enzymes are proteins functioning as catalysts that speed up reactions by lowering the activation energy. Hope this helps! :)

why do the isotopes of a particular element behave differently in nuclear reactions but the same in chemical reactions? chemical reactions involve changes to electrons in an atom; isotopes do not differ in electrons, and so they react the same way during chemical changes.