Antibiotics and antibiotic resistance. (Penicillin)

General Notes

Alexander Fleming discovered Penicillin in 1928, this was the first ever antibiotic put into use to treat infections.

Antibiotics account for one in every six prescriptions written by Doctors every day.

How they work

In short antibiotics prevent bacteria from making normal cell walls.

In bacterial cells, as in plant cells, osmosis is constantly allowing water to enter, this entry of water would usually cause the cell to burst- this process is called osmotic lysis. The only way it doesn't burst is due to the bacterial cell wall, this is made of a tough material that does not easily break or stretch. This denies to entry of water as the cell wall prevents expansion and in turn prevents osmotic lysis.

Most antibiotics kill and prevent bacteria from forming new cell walls, by inhibiting synthesis and formation of important peptide cross-linkages. This makes the walls weaken and unable to withstand pressure, as a result they are unable to prevent water entry and osmotic…