All enzyme's are catalysts for certain chemical reactions. Each enzyme will only work with a certain substrate one analogy being that the enzyme is a key and the substrate is a keyhole, and each enzyme has a unique enzyme.
Catalyst
A substance that speeds up a chemical reaction is known as a CATALYST.
catalyst-by lowering activation energy
the region where a reactant binds to an enzyme is known as the active site
active site. This is where the reaction takes place and the substrate interacts with the enzyme to form the product. The active site has a specific shape that fits the substrate, allowing for the reaction to occur.
A substance labeled as a catalyst is also known as a chemical agent that speeds up a reaction without being consumed in the process. Catalysts work by lowering the activation energy required for a reaction to occur and can be reused multiple times.
Reactants. "Substrate" is another possibility.
A lot of homework questions, today. I wouldn't answer but the questions are always written poorly due to teachers not understanding their subject matter. Your teacher probably wants you to say "An enzyme." http://en.wikipedia.org/wiki/Enzyme
The point or site on a substrate where an enzyme acts is known as the active site. This is where the enzyme binds to the substrate molecule to facilitate the chemical reaction. The active site is specific to each enzyme and plays a crucial role in catalyzing the reaction.
The substrate is the molecule affected by the enzyme.
There is no chemical of that sort. The chemical general name for the substance which speeds up the reaction is known as a catalyst.
A Catalyst.From wikipedia: "Catalysis is the process in which the rate of a chemical reaction is increased by means of a chemical substance known as a catalyst. Unlike other reagents that participate in the chemical reaction, a catalyst is not consumed by the reaction itself. The catalyst may participate in multiple chemical transformations."http://en.wikipedia.org/wiki/Catalyst