Why are the intermolecular bonds important in enzymes?
Noncovalent interactions are a very big part of why enzymes fold the way they do and why substrates bind to the active sites they do. Take careful note that enzymes fold because of entropy in the system increasing due to the hydrophobic effect. The way enzymes fold in such conformations are these intermolecular forces between residues.
Moreover, certain interactions, like hydrogen bonding, can facilitate catalytic triads (e.g. the Asp-His-Ser in serine proteases) to kick off the catalytic cycle of enzymes. Moreover, they can stabilize intermediates and/or bind to discriminator sites in the substrates.