Catalysts & Enzymes
Existence would be much different if chemical reactions transpired at their nominal rate. Instead, Nature quickens the pace with catalysts, which arise in a wide variety of chemical contexts. If not for catalysis, life would not be possible.
Catalysts promote chemical reactions. The term promote is used because it is possible for a reaction to happen without a catalyst, but the likelihood of non-catalytic reaction is analogous to a coin flip resulting in the coin standing on edge: not likely.
Catalysts lower the activation energy required for a reaction to occur. In organic chemistry, that role is played by proteins known as enzymes.