Which of the following enzyme inhibitors binds through covalent bonds?

• A. Reversible
• B. Irreversible

Answer: (B)

Verified step by step guidance

1. Understand the difference between reversible and irreversible enzyme inhibitors. Reversible inhibitors bind to enzymes through non-covalent interactions such as hydrogen bonds, ionic bonds, and hydrophobic interactions, allowing them to dissociate from the enzyme. Irreversible inhibitors, on the other hand, form covalent bonds with the enzyme, leading to permanent inactivation.
2. Consider the nature of covalent bonds. Covalent bonds involve the sharing of electron pairs between atoms, creating a strong and stable connection that is not easily broken under physiological conditions.
3. Identify the characteristics of irreversible inhibitors. These inhibitors typically form a covalent bond with a specific amino acid residue in the enzyme's active site, often leading to a permanent change in the enzyme's structure and function.
4. Recognize examples of irreversible inhibitors. Common examples include aspirin, which acetylates a serine residue in the active site of cyclooxygenase, and penicillin, which forms a covalent bond with a serine residue in bacterial transpeptidase enzymes.
5. Conclude that irreversible inhibitors are the type of enzyme inhibitors that bind through covalent bonds, as opposed to reversible inhibitors, which do not form such stable, permanent interactions.