What this means is that these reactions will occur spontaneously even outside of a living organism. If cells did not have ways of speeding up catabolism , life would be nearly impossible.
Enzymes accelerate almost all biological reactions.
Enzyme structure Enzymes are proteins, which themselves are polymers of amino acids. For more information on Protein Structure see the bacterial structure section. Some enzymes have extra molecules associated with them, besides amino acids, that assist in the reaction they carry out. The protein portion of an enzyme is called the apoenzyme . A cofactor is the non-protein part of an enzyme.