1. Covalent and non-covalent interactions are important for macromolecule structure and function. Covalent bonds strongly bind atomic subunits while non-covalent bonds like hydrogen bonding and hydrophobic interactions more weakly stabilize macromolecule structures.
2. Covalent bonds like peptide bonds link amino acids into protein chains. Non-covalent interactions are crucial for protein folding and binding specificity. Though individually weak, many non-covalent bonds cooperatively bind molecular surfaces.
3. Covalent drugs form irreversible complexes with target proteins, while non-covalent drugs reversibly inhibit enzymes through competitive, noncompetitive, or uncompetitive binding. Examples are covalent penicillin and non-covalent acetylcholinester