Which enzyme function is disrupted by antibiotics that target β-lactams?

Antibiotics that target β-lactams specifically disrupt the function of penicillin-binding proteins (PBPs). These proteins are crucial for the synthesis and maintenance of bacterial cell walls. β-lactam antibiotics, including penicillin, bind to the active sites of PBPs, inhibiting their activity and ultimately preventing the formation of cross-links in the peptidoglycan layer of the bacterial cell wall. This disruption leads to a weakened cell wall structure, making the bacteria susceptible to osmotic pressure and resulting in cell lysis and death.

By targeting PBPs, β-lactam antibiotics effectively halt bacterial growth and replication. This mechanism is significant in the treatment of various bacterial infections, highlighting the importance of PBPs in maintaining bacterial integrity.

The other options, while representing important enzymes in different biological pathways, do not relate to the mechanism of action of β-lactam antibiotics. Hexokinase is involved in glucose metabolism, dihydrofolate reductase plays a role in folate metabolism, and DNA ligase is essential for DNA replication and repair, but none of these are affected by β-lactam-based antibiotics.