Final answer:
Enzymes are primarily made from proteins and may require cofactors or coenzymes to function optimally. They lower the activation energy for biochemical reactions.
Step-by-step explanation:
Most enzymes are made from proteins, which are macromolecules consisting of long chains of amino acids. These proteins are responsible for catalyzing biochemical reactions by substantially lowering the activation energies needed for reactions to proceed.
Enzymes bind to their substrates at an active site and can either require the presence of helper molecules, such as cofactors or coenzymes, to function optimally. Cofactors may be inorganic ions, like iron (Fe²⁺) and magnesium (Mg²⁺), while coenzymes are typically organic molecules, many of which are derived from vitamins.