AP BIOLOGY

Detailed explanation-1: -A catalyst is a substance that speeds up a chemical reaction, or lowers the temperature or pressure needed to start one, without itself being consumed during the reaction. Catalysis is the process of adding a catalyst to facilitate a reaction.

Detailed explanation-2: -Catalysts typically speed up a reaction by reducing the activation energy or changing the reaction mechanism. Enzymes are proteins that act as catalysts in biochemical reactions. Common types of catalysts include enzymes, acid-base catalysts, and heterogeneous (or surface) catalysts.

Detailed explanation-3: -A catalyst is a substance that speeds up the rate of a chemical reaction but is not consumed during the course of the reaction. A catalyst will appear in the steps of a reaction mechanism, but it will not appear in the overall chemical reaction (as it is not a reactant or product).

Detailed explanation-4: -Most solid catalysts are metals or the oxides, sulfides, and halides of metallic elements and of the semimetallic elements boron, aluminum, and silicon.

Detailed explanation-5: -Iron-used as a catalyst for the synthesis of ammonia from nitrogen and hydrogen, through the Haber process. Zeolites-commonly used as catalysts for organic reactions such as petroleum cracking, and the synthesis of hydrocarbons.