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Name: sara
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could you please explain fully how ampicillian destroys E.coli cells?

Ampicillin is an antibiotic belonging to the group of beta-lactam antibiotics. These will kill Gram-negative bacteria to which E.coli and Salmonella belong. The antibiotic prevents the formation of peptidoglycan, an essential building block of the cell membrane. So the antibiotic prevents growth of cells.

You can read more about antibiotics and how bacteria can become resistant against them at the Virtual Bacteria of Bacteria:

Dr. Trudy wasenaar

Unfortunately, I don't have my micro books with me, but I'll try. Bacteria have a unique compound in their cell walls called peptidoglycan. It is made of 2 types of sugar residues that are cross-linked (like a chain link fence) by tetrapeptides. Penicillin prevents the crosslinking of the sugars by breaking the tetrapeptides. These antibiotics are more effective against gram positive organisms (such as Staph.) than gram negative organisms (such as E coli) because gram pos. have more peptidoglycan in their cell walls. Some bacteria have adapted to this situation by having an enzyme called beta-lactamase that breaks the structure of the antibiotic open rendering it ineffective. I'm pretty sure ampicillin is a penicillin derivative and therefore has the same mode of action, but I would check to make sure if I were you.

Van Hoeck

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