Why is peptidoglycan a redeeming feature within bacteria?
Peptidoglycan is the main structural component that both Gram-positive and Gram-negative bacteria have evolved to support and stabilize the cell membrane. Without peptidoglycan, the bacterial cell would literally collapse in on itself (which is why targeting it with antibiotics is so detrimental). Peptidoglycan is essential to the strength in the cell wall for almost every known bacterial species. However, do note that some antibiotics that target peptidoglycan are not terribly effective against Gram-positives because they have so MUCH peptidoglycan. Also, many bacterial pathogens have evolved changes in their penicillin binding proteins which prevent the beta-lactam antibiotics from hijacking PG synthesis. This is how they circumvent antibiotics like penicillin and develop resistance.
