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**     ﻿ ﻿ ﻿ ﻿ ﻿ ﻿ My favorite molecule: penicillin**



What is penicillin?
====Penicillin (sometimes abbreviated PCN or pen) is a group of antibiotics derived from Penicillium fungi. They include penicillin G, procaine penicillin , and penicillin V. Procaine penicillin and have the same antibacterial activity as penicillin G but act for a longer period. Penicillin V is less active against Gram-negative bacteria than benzyl penicillin. Benylpenicillin, procaine penicillin and benzathine penicillin are given by injection, but penicillin V is given orally.The term " penam " is used to describe the core skeleton of a member of a penicillin antibiotic. This skeleton has the molecular formula R-C9H11N2O4S, where R is a variable side chain. ====

History and Discovery of Penicillin



In 1830, infectious diseases caused by bacteria and other microorganisms were a major cause of death, and most shockingly, only fifty percent of the population lived past the age of twenty five. Hospitals were full of people with blood poisoning contracted from a cut or a scratch, and doctors could do little for them but wait and hope. This condition continues until 1928, that penicillin, the first true antibiotic, was discovered by Alexander Fleming, Professor of Bacteriology at St. Mary's Hospital in London. Then Penicillin heralded the dawn of the antibiotic age. Before its introduction there was no effective treatment for infections such as pneumonia, gonorrhea, or rheumatic fever. Returning from holiday on September 3, 1928, Fleming began to sort through petri dishes containing colonies of Staphylococcus, bacteria that cause boils, sore throats, and abscesses. He noticed something unusual on one dish. It was dotted with colonies, save for one area where a blob of mold was growing. The zone immediately around the mold - later identified as a rare strain of Penicillium notatum - was clear, as if the mold had secreted something that inhibited bacterial growth. Fleming found that his "mold juice" was capable of killing a wide range of harmful bacteria, such as streptococcus and the diphtheria bacillus. The difficult task of isolating pure penicillin from the mold juice is that it was proved to be very unstable, and they were only able to prepare solutions of crude material to work with.

Why penicillin

I choose this molecule because I am so interested about how it works through our bodies and its cool medical uses. Chemically, penicillin is not a single compound but a group of closely related compounds, all with the same basic ring-like structure derived from two amino acids via a intermediate.

Penicillin is a broad-spectrum antibiotics commonly used in clinic and it’s effective, cheap, anti-infective and has fewer side effects. For most bacteria, some bacteria, spirochetes and release of various strains, penicillin have strong effects. it was found that the first few years of basic usage. Recently, clinical practice shows that penicillin is the treatment of peptic ulcer medicine. And children although are fear of the injection of penicillin, they are really useful. Many people were saved from previously considered deadly infections by penicillin (such as those due to Staphylococcus), since the 2nd World War when the antibiotic started being produced industrially.



How it works

Now, let me tell you how it works in our bodies.Overall, there are a few main and important steps to the biosynthesis of penicillin G :



While drug resistance, particularly strains increasingly immune to penicillin, has become big news recently, the development is long in coming. Since penicillium uses penicillin for the same purposes as humans, bacteria has already developed a set of defenses. Many bacteria produce penicillinase, which rots away the penicillin clinging to transpeptidase. This evolutionary combat highlights another method through which penicillin and its derivatives operate. Because bacteria has developed such defenses including double cell-walls which can't be fully dissolved, penicillin has evolved to work in concert with other chemicals such as aminoglycosides. Thus penicillin operates on several levels. In conjunction with aminoglycosides penicillin disrupts protein synthesis and even the reproduction of organelles within the bacterium.

Read more: [|How Does Penicillin Work? | eHow.com] []  <span style="display: block; height: 1px; left: 20px; overflow: hidden; position: absolute; top: 720px; width: 1px;">

<span style="background-color: transparent; color: #000000; display: block; overflow: hidden; text-align: left; text-decoration: none;">While drug resistance, particularly strains increasingly immune to penicillin, has become big news recently, the development is long in coming. Since penicillium uses penicillin for the same purposes as humans, bacteria has already developed a set of defenses. Many bacteria produce penicillinase, which rots away the penicillin clinging to transpeptidase. This evolutionary combat highlights another method through which penicillin and its derivatives operate. Because bacteria has developed such defenses including double cell-walls which can't be fully dissolved, penicillin has evolved to work in concert with other chemicals such as aminoglycosides. Thus penicillin operates on several levels. In conjunction with aminoglycosides penicillin disrupts protein synthesis and even the reproduction of organelles within the bacterium.

Read more: [|How Does Penicillin Work? | eHow.com] []  <span style="display: block; height: 1px; left: 20px; overflow: hidden; position: absolute; top: 545px; width: 1px;">

<span style="background-color: transparent; color: #000000; display: block; overflow: hidden; text-align: left; text-decoration: none;">Penicillin operates by dissolving the cell wall of bacteria, dispersing its cytoplasm and other cell systems. One essential component of the bacterial cell wall is transpeptidase, which accepts molecules of penicillin as a substrate attachment. The penicillin activates, preventing peptidoglycan reactions that strengthen links in the cell wall. This leads inevitably to cytolysis and cell death.

Read more: [|How Does Penicillin Work? | eHow.com] []

Penicillin is bactericidal because it destroys the cell wall of microorganisms by inactivating an enzyme called //transpeptidase//, required for the cross linking of bacterial cell walls. The enzyme mistakenly accepts the penicillin as a substrate (or activation component) and is then rendered ineffective. This prevents synthesis and repair of the bacterial cell wall, causing the bacteria to burst. Bacterial cell wall inhibitors such as pencillins are some of the most powerful and broad-spectrum antibiotics. However, they can only destroy actively growing bacteria, not dormant colonies or spores. Thus taking penicillin cannot prevent illness and the correct duration and dosage of medication is important to fight an existing infection.

<span style="display: block; height: 1px; left: 20px; overflow: hidden; position: absolute; top: 720px; width: 1px;">

<span style="background-color: transparent; color: #000000; display: block; overflow: hidden; text-align: left; text-decoration: none;">While drug resistance, particularly strains increasingly immune to penicillin, has become big news recently, the development is long in coming. Since penicillium uses penicillin for the same purposes as humans, bacteria has already developed a set of defenses. Many bacteria produce penicillinase, which rots away the penicillin clinging to transpeptidase. This evolutionary combat highlights another method through which penicillin and its derivatives operate. Because bacteria has developed such defenses including double cell-walls which can't be fully dissolved, penicillin has evolved to work in concert with other chemicals such as aminoglycosides. Thus penicillin operates on several levels. In conjunction with aminoglycosides penicillin disrupts protein synthesis and even the reproduction of organelles within the bacterium.

Read more: [|How Does Penicillin Work? | eHow.com] []

<span style="color: #008000; font-family: 'Comic Sans MS',cursive; font-size: 120%; margin: 0cm 0cm 0pt;">Do you know?

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<span style="font-family: Tahoma,Geneva,sans-serif; font-size: 110%; margin: 0cm 0cm 0pt;">One type of penicillin is Penicillium glaucum, which is a mold which is used in the making of some types of blue cheese, including Bleu de Gex , Rochebaron and some varieties of Bleu d'Auvergne and Gorgonzola. (Other blue cheeses, including Bleu de Bresse, Bleu du Vercors-Sassenage , Brebiblu , Cambozola , Cashel Blue , Danish blue , Fourme d'Ambert , Fourme de Montbrison , Lanark Blue , Roquefort , Shropshire Blue and Stilton use Penicillium roqueforti .) Than is popular in Europe, yet few people know that there is chemical compound in it called " penicillin"!!!!! Emmmmm.....Yummy!!

<span style="color: #008000; font-family: 'Comic Sans MS',cursive; font-size: 120%;">Resources <span style="color: #008000; font-family: Tahoma,Geneva,sans-serif; font-size: 120%; margin: 0cm 0cm 0pt;">[] <span style="font-family: Tahoma,Geneva,sans-serif; font-size: 110%; margin: 0cm 0cm 0pt;">[] <span style="font-family: Tahoma,Geneva,sans-serif; font-size: 110%; margin: 0cm 0cm 0pt;">[] <span style="font-family: Tahoma,Geneva,sans-serif; font-size: 110%; margin: 0cm 0cm 0pt;">[] <span style="font-family: Tahoma,Geneva,sans-serif; font-size: 110%; margin: 0cm 0cm 0pt;">http://en.wikipedia.org/wiki/Penicillium_glaucum <span style="font-family: Tahoma,Geneva,sans-serif; font-size: 110%; margin: 0cm 0cm 0pt;">Le Couteur and Burrenson, 2003, p. 196-7). <span style="font-family: Tahoma,Geneva,sans-serif; font-size: 110%; margin: 0cm 0cm 0pt;">Schlessinger, 1993, p. 90