Identify the two important classes of catalysts. Analyze the chemical reactions that take place when a biological catalyst combines with a reactant (substrate) to form an unstable intermediate.

The two important classes of catalysts are biological catalysts, known as enzymes, and non-biological catalysts, often referred to as inorganic catalysts.

When a biological catalyst, such as an enzyme, combines with a reactant (substrate) to form an unstable intermediate, it undergoes a series of chemical reactions. These reactions typically involve the active site of the enzyme and can be summarized in the following steps:

1. Substrate binding: The substrate molecules bind to the active site of the enzyme through non-covalent interactions, such as hydrogen bonding, electrostatic interactions, and hydrophobic interactions. This binding brings the substrate molecules into close proximity, facilitating the reaction.

2. Transition state stabilization: The enzyme stabilizes the transition state of the reaction, which is the highest energy state along the reaction pathway. This stabilization lowers the activation energy required for the reaction to occur, making it more favorable.

3. Catalysis: The enzyme facilitates the conversion of the substrate into the product(s) by providing an alternative reaction pathway with a lower activation energy. It can achieve this through various mechanisms, including acid-base catalysis (donating or accepting protons), covalent catalysis (forming temporary covalent bonds), and metal ion catalysis (involving metal ions within the active site).

4. Product formation: Once the reaction is complete, the enzyme releases the product(s) from the active site, allowing them to diffuse into the surrounding solution.

Throughout this process, the enzyme itself remains unchanged and can be reused to catalyze multiple rounds of the same reaction. The specificity of the enzyme for its substrate(s) is determined by the complementarity between the active site and the substrate molecules, ensuring that the enzyme selectively binds and catalyzes only specific reactions.

The two important classes of catalysts are biological catalysts, known as enzymes, and non-biological catalysts.

When a biological catalyst combines with a reactant (substrate) to form an unstable intermediate, a chemical reaction called enzymatic catalysis occurs. This process involves several steps:

1. Substrate Binding: The substrate molecules bind to the active site of the enzyme through non-covalent forces like hydrogen bonding, electrostatic interactions, and van der Waals forces.

2. Transition State Formation: The enzyme facilitates the formation of a transition state, which is a highly unstable intermediate between the reactants and the products. This occurs by interacting with the substrate's chemical bonds and stabilizing or destabilizing them.

3. Reaction Facilitation: The enzyme lowers the activation energy required for the reaction to proceed, allowing it to occur at a faster rate. This is achieved by providing an alternative reaction pathway with a lower energy barrier.

4. Product Formation: The enzyme modifies the chemical structure of the substrate molecules, leading to the formation of products. This can involve breaking or forming new chemical bonds.

5. Release of Products: Once the reaction is complete, the enzyme releases the products, allowing it to bind to another substrate molecule and repeat the catalytic cycle.

Overall, the combination of a biological catalyst (enzyme) with a substrate enables the formation of an unstable intermediate and lowers the activation energy, making the reaction more efficient. This process is crucial for various biological processes, including metabolism, DNA replication, and protein synthesis.

Surely you don't expect us to write this for you. Here is a site that contains almost anything you want to know about catalysts.

http://antoine.frostburg.edu/chem/senese/101/reactions/faq/examples-of-catalysts.shtml