Final answer:
Enzymes are proteins made up of amino acid chains connected by peptide bonds and act as catalysts in biological reactions.
Step-by-step explanation:
Enzymes belong to the major organic molecule group called proteins, all of which are made up of chains of amino acids held together by peptide bonds. Enzymes act as catalysts, speeding up chemical reactions by lowering the activation energy required for the reaction to occur. As proteins, enzymes consist of long chains of amino acids, which fold into specific three-dimensional structures dictating their function in catalyzing biological processes.