Answer:
C. cell wall cross-link formation
Explanation:
Penicillin is an antibiotic that kills the bacteria by inhibiting the enzyme that catalyzes the formation of peptide cross-links between N- acetyl glucosamine and N-acetylmuramic acid of peptidoglycan of a bacterial cell wall. The enzyme is called transpeptidase. These cross-links hold the sheets of these monomers and form the rigid peptidoglycan layer.
In the absence of the cross-links, Gram-positive bacteria completely lose the cell wall and become protoplast while the Gram-negative bacterial cells remain covered with the outer membrane alone. These bacterial cells lyse when placed in a hypotonic solution.
