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The labile p-lactam ring in penicillin reacts with a serine residue in the transpeptidase as shown below. This reaction is irreversible and so the growth of the bacterial cell wall is inhibited. The resulting complex is stable to water and remains attached to the polypeptide chain. The peptidoglycan transpeptidase is not needed in animals as their cells do not have cell walls. Therefore the penicillin can safely disrupt the bacterial cell wall biosynthesis without harming existing cells in the body. 囚N为了帮助保护您的隐私, Power Point已阻止自动下载此图片
The labile β-lactam ring in penicillin reacts with a serine residue in the transpeptidase as shown below. This reaction is irreversible and so the growth of the bacterial cell wall is inhibited. The resulting complex is stable to water and remains attached to the polypeptide chain. The peptidoglycan transpeptidase is not needed in animals as their cells do not have cell walls. Therefore, the penicillin can safely disrupt the bacterial cell wall biosynthesis without harming existing cells in the body
Penicillin g and v are only active against Gram Positive bacterial cells, which have an exposed layer of peptidoglycan around the outside of the cell wall as shown above. gram Negative bacteria have a more complicated composition, which Penicillin G and v can not destroy Penicllin-binding poteins, PBPs R OH O COOH PBP
Penicllin-binding poteins,PBPs N O R COOH H NH3 PBPs OH Penicillin G and V are only active against Gram Positive bacterial cells, which have an exposed layer of peptidoglycan around the outside of the cell wall, as shown above. Gram Negative bacteria have a more complicated composition, which Penicillin G and V can not destroy
Penicllin Nature Penicillin(Fermentation-Derived Penicillins) B Penicillin was discovered by alexander Fleming in 1929
Penicliins Nature Penicillin (Fermentation-Derived Penicillins) Penicillin was discovered by Alexander Fleming in 1929
Fleming found that it was effective against many gram positive bacteria in laboratory conditions, and he even used locally applied, crude preparations of this substance, from culture filtrates, to control eye infections. However, he could not purify this compound because of its instability, and it was not until the period of the second world War(1939-1945) that two other British scientists, Florey and Chain, working in the USA, managed to produce the antibiotic on an industrial scale for widespread use. In recognition for his contribution, Alexander Fleming was knighted in 1944. With Chain and florey he was awarded the Nobel prize in 1945 One sometimes finds what one is not looking for
Fleming found that it was effective against many Gram positive bacteria in laboratory conditions, and he even used locally applied, crude preparations of this substance, from culture filtrates, to control eye infections. However, he could not purify this compound because of its instability, and it was not until the period of the Second World War (1939-1945) that two other British scientists, Florey and Chain, working in the USA, managed to produce the antibiotic on an industrial scale for widespread use. In recognition for his contribution, Alexander Fleming was knighted in 1944. With Chain and Florey he was awarded the Nobel Prize in 1945. "One sometimes finds what one is not looking for