What are enzymes ?
Enzymes are macromolecular biological catalysts. The molecules upon which enzymes may act are called substrates and therefore the enzyme converts the substrates into different molecules referred to as products.
Almost all metabolic processes within the cell need enzyme catalysis so as to occur at rates fast enough to sustain life. Metabolic pathways depend on substrate enzymes to catalyze individual steps. Enzymes are known to catalyze quite 5,000 biochemical reaction types.
Most enzymes are proteins, although a couple of are catalytic RNA molecules. The latter are called ribozymes. Enzymes’ specificity comes from their unique three-dimensional structures.