enzyme By Ivan Suarez Robles 16 Nov, 2010 A protein that speeds up a chemical reaction. Enzymes do their work without being changed or used up in the process.Related Articles: Glossary: suberoylanilide hydroxamic acid (SAHA)Glossary: substrateGlossary: DNA PolymeraseStories of HOPES: "Like Father Like Son?"Isis Pharmaceutical Trial