The molecular structures of two ‘penicillin-like’ compounds, A and B. in the compound A the C-C-N ring is intentionally bold, as is the C-C-C-C-N ring in compound B.

By comparing these structures assess which of A and B, might be (i) more active than penicillin against bacteria and (ii) less active than penicillin against bacteria.

i have to Explain how i arrived at the decisions by firstly reviewing how and why penicillin acts against bacteria and then explaining why compounds A and B might be more or less active. (No more then 300 word).

The key feature of penicllin compounds is the beta lactam ring which inhibits formation of cell wall structures. So the reactivity of the beta lactam ring is the key feature. To turn the question back to you which ring size, 3 or 5, is more/less reactive (=more/less strained) than the 4 membered ring of penicillin?