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4.6 The Cell Wall of Bacteria (cont’d):
- D- amino acids, eg D-alanine & diaminopimelic acid, DAP – only in CW
- Short peptides (aka 4 amino acids, tetrapeptides) are attached to M and interlink with a carboxyl group of an amino acid of an adjacent M to form a direct or indirect tetrapeptide bridge.
- Transpeptidase builds peptide bridges in actively dividing cells; penicillin binds to it stoping cell wall synthesis.
- Autolysins restructure and reshape cell walls by breaking specific bonds in the peptidoglycan in actively growing cells; in old cells this results in cell wall weakening and cell lysis