Hydratases

Definition

Hydratases are enzymes that catalyze the addition of water (H2O) to a substrate, typically an alkene or a nitrile, to form a new product. These enzymes play a crucial role in the context of the reaction stereochemistry involving the addition of water to an achiral alkene.

5 Must Know Facts For Your Next Test

1. Hydratases catalyze the addition of water to an alkene in a Markovnikov-type regiochemistry, resulting in the formation of an alcohol product.
2. The addition of water to an achiral alkene using a hydratase enzyme proceeds with overall retention of stereochemistry.
3. Hydratases can be classified based on the specific type of reaction they catalyze, such as alcohol dehydrogenases, which catalyze the oxidation of alcohols to aldehydes or ketones.
4. The active site of hydratases often contains metal ions, such as zinc, which help to activate the water molecule and facilitate the addition to the alkene.
5. Hydratases are found in various organisms, including bacteria, fungi, and higher plants, and play important roles in diverse metabolic pathways.

Review Questions

• Explain the role of hydratases in the addition of water to an achiral alkene.
  • Hydratases are enzymes that catalyze the addition of water (H2O) to an achiral alkene. This reaction proceeds with a Markovnikov-type regiochemistry, resulting in the formation of an alcohol product. The key feature is that the addition of water occurs with overall retention of stereochemistry, meaning the final alcohol product has the same stereochemical configuration as the starting alkene.
• Describe the active site features of hydratases that enable the addition of water to alkenes.
  • The active site of hydratases often contains metal ions, such as zinc, which help to activate the water molecule and facilitate its addition to the alkene. These metal ions polarize the water molecule, making the oxygen more electrophilic and able to attack the alkene. The specific orientation and interactions within the active site also play a crucial role in determining the regiochemistry and stereochemistry of the final product.
• Analyze the significance of the retention of stereochemistry in the addition of water to achiral alkenes catalyzed by hydratases.
  • The retention of stereochemistry in the addition of water to achiral alkenes catalyzed by hydratases is significant because it allows for the predictable and controlled formation of specific stereoisomers of the alcohol product. This is important in organic synthesis, as it enables the selective preparation of desired stereochemical configurations, which can be crucial for the synthesis of complex natural products or pharmaceutically active compounds. The ability of hydratases to maintain the stereochemical integrity of the starting material highlights their importance in organic chemistry and biochemistry.

Related terms

Regiochemistry: The study of the relative position of atoms in the product of a chemical reaction.

Stereochemistry: The study of the spatial arrangement of atoms in molecules and how it affects their chemical properties.

Achiral: A molecule that is not chiral, meaning it has no non-superimposable mirror image.