• Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

Penicillin - its discovery, properties and uses.

Extracts from this document...


Introduction Penicillin is a familiar word to everyone. The first idea that comes to people's mind is Penicillin is a group of antibiotics, as Penicillin is a very common antibiotic that kills bacteria. Apart from killing bacteria, what else do people know? Probably is nothing. In this project, I would like to find out what do Penicillin is and how people discovery Penicillin. First of all, go with the basic thing, what antibiotic1 is. Antibiotics are molecules that stop microbes, both bacteria and fungi, from growing or kill them outright. Antibiotics can be classified as either bactericidal or bacteriostatic. Antibiotics that stop bacteria from growing are bacteriostatic. Antibiotics that cause bacterial cell death are bactericidal. They lower the bacterial count, penicillin, is bactericidal. Some antibiotics can display bacteriostatic activity in some circumstances and bactericidal activity in other, where sufficient damage to one or more cell pathways or structures occurs such that a net bactericidal response is triggered. Many antibiotics are bacteriostatic at low concentrations and bactericidal at higher concentrations2. This distinction is often not important clinically. Antibiotic can either be natural products or man-made synthetic chemicals. Most of the antibiotic introduced into human clinical use to treat infections disease in the past 60 years have been natural products, elaborated by the one microorganism in a particular habitat and set of environmental condition to affect neighboring microbes, either to regulate their growth or to rigger their elimination. Antibiotic natural products are produced by the both bacteria and fungi, with the major group of antibiotic-producing bacteria being the actinomycetes.3 When a new antibiotic molecule was detected in a microbial culture broth or a screen in a synthetic medicinal chemistry program, it will compare against benchmark antibiotics with known mechanisms of action. A novel mechanism suggested a new target could be delineated through biochemical analysis. In turn, knowledge of the targets and mechanism of action of major antibacterial drug classes also gave a range of assays that would allow categorization of newly discovered antibacterial by mechanism of action. ...read more.


Fleming could easily show that it did no harm to white blood cells: this was important because the laboratory he worked in, handed by Almroth Wright, had long been committed to the idea that the key to effective treatment was to mobilize the body's own capacity for defense. Fleming himself, during the First World War, had studied infections in soldiers' wounds and had argued that conventional antiseptics both killed off white blood cells faster than they killed bacteria, and failed to penetrate into the jagged interstices of gumshot wounds: they were, he thought, positively fostering infection. He could also striaghtforwardly show, by injecting the broth derived from his mould into a very small number of mice and rabbits, that it was not toxic. And he could also show that it quickly lost its anti-bacterial effect when mixed with disgestive juices: there would be no point in taking it as a pill. Fleming was surely moving towards injecting ''mould broth filtrate'' - penicillin into infected animals to see if would cure them. By April 1929, Fleming seems to have lost all interest in injecting penicillin into bloodstream. As penicillin took around four hours to kill bacteria, but tests showed that both in animals and in the test tube it ceased to be active in blood after two hours. This seems to have persuaded him that it would be pointless introducing penicillin into a diseased body. The possibility that penicillin might have a future use as an antiseptic was mentioned in Fleming's first and only major publication on his new discovery, which appeared in 1929. He wrote: "It was suggested that it may be an efficient antiseptic for application to, or injection into, areas infected with penicillin-sensitive microbes." Between 1930 and 1940, 18Fleming made no effort to develop a clinical use of penicillin. Throughout this period, however, he employed it regularly for the one use that was outlined in his key publication. While penicillin killed many bacteria, it did not kill a bacterium called Pfeiffer's bacterium. ...read more.


Other antibiotics became available after penicillin had been discovered, but before it was available to the public. However, they were more limited in their use than penicillin was, so a lot of people will not count Salvarsan as the first antibiotic. The development of antibiotics is one of the most successful stories in the history of medicine, but it is unclear whether its ending will be a completely happy one25. As improper use of penicillin would lead to its becoming ineffective. The danger was not taking too much, it was in taking too little to kill the bacteria but 'enough to educate them to resist penicillin'. This is unfortunate because there are not many ways to fight microbes, and fewer and fewer antibiotics are being developed. Also, develop a new antibacterial drug is largely economic26. As antibiotics often are good for only two or three years before bacteria become resistant to them, pharmaceutical companies do not have the financial incentive to develop new ones. When a company loses interest, its researcher adept at developing and testing antibiotics must move to more profitable areas. 1 "Antibiotics: actions, origins, resistance" by Christopher Walsh 2 "Pharmacology - for the health care professions" by Christine M. Thorp 3 "Encyclopaedia of antibiotics" by Glasby, John S 4 "Antibiotics: actions, origins, resistance" by Christopher Walsh 5 "Pharmacology - for the health care professions" by Christine M. Thorp 6 http://www.news-medical.net/health/Penicillin-Biosynthesis.aspx 7 http://www.experiment-resources.com/history-of-antibiotics.html 8 "Natural Alternative to antibiotics" by Dr. John McKenna 9 http://www.associatedcontent.com/article/100649/a_brief_history_of_antibiotics.html 10 "Sir John Burdon Sanderson" by S. MacNalty 11 http://www.associatedcontent.com/article/100649/a_brief_history_of_antibiotics.html 12 "Bad Medicine" by David Wootton 13 http://www.associatedcontent.com/article/100649/a_brief_history_of_antibiotics.html 14 "Natural Alternatives to Antibiotics" By Dr. John McKenna 15 http://www.botany.hawaii.edu/faculty/wong/BOT135/Lect22.htm 16 http://www.wipo.int/wipo_magazine/en/pdf/2000/wipo_pub_121_2000_07-08.pdf 17 "Bad Medicine" by David Wootton 18 "Natural Alternative to antibiotics" by Dr. John McKenna 19 "Bad Medicine" by David Wootton 20 "The Mould in Dr. Florey's Coat" by Eric Lax 21 "The Mould in Dr. Florey's Coat" by Eric Lax 22 http://www.wisegeek.com/how-was-penicillin-discovered-and-developed.htm 23 "The Mould in Dr. Florey's Coat" by Eric Lax 24 http://www.drugs.com/penicillin.html 25 http://www.guardian.co.uk/ - 9th September,2010 by Sarah Boseley 26 Interview with a pharmacist - Sherrie Hair ?? ?? ?? ?? ...read more.

The above preview is unformatted text

This student written piece of work is one of many that can be found in our International Baccalaureate Biology section.

Found what you're looking for?

  • Start learning 29% faster today
  • 150,000+ documents available
  • Just £6.99 a month

Not the one? Search for your essay title...
  • Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

See related essaysSee related essays

Related International Baccalaureate Biology essays

  1. Marked by a teacher

    Experiment to investigate the effect of different antibiotics on the bacteria Bacillus subtilis:

    4 star(s)

    Antibiotics are among the most frequently prescribed medications in modern medicine. They cure disease by killing or injuring bacteria. The first antibiotic was penicillin, discovered accidentally from a mold culture. Penecillium fungus produces penicillin to kill bacteria. Today, over 100 different antibiotics are available to cure minor discomforts as well as life-threatening infections.

  2. Biology Lab Report - Effects of Mouthwash on Oral Bacteria

    Which mouthwash was least effective at killing on slowing growth of mouth bacteria? Support your answers using your observations and data. Mouthwash A: Oral B- Natural Mint. It showed an average zone of inhibition of 0.36cm, the lowest average zone of inhibition on bacteria compared to the other mouthwashes.

  1. The Effects of Salinity on Wheat Germination

    Moreover, seeds in the 5% solution may not have had a water concentration of 5% the whole time due to tendency of salt to form crystals and be absorbed into fibrous material and thus some of the salt may have been trapped in the paper towel and may not have contributed to the solution.

  2. What is the effect of different body positions i.e. lying down, sitting and standing ...

    support the hypothesis stated as they revealed that by conventional criteria, the difference between the means of the diastolic and systolic pressures for participants standing up and sitting down was considered to be insignificant. A reason for this may be that the participants only stayed in the different body positions

  1. biology extended essay - How different diets: vegetarian, vegan and a meat centered diet ...

    [8] From the sample result above, one can calculate for instance a 95% confidence level for each of the three population category assuming the populations are normally distributed. 1) Vegetarian: Mean for the body mass index is 21.13 with Standard Deviation 3.1825 Since we chose 95% Confidence level, then we have 5 degrees of freedom.

  2. How the Heart Works

    * Pericarditis - This is when the pericardium becomes inflamed which is often a result of a viral infection or a heart attack. * Heart failure - The hearts inability to effectively pump blood to the lungs and the body's tissues.

  1. The effect of antibacterial toothpastes on Micrococcus luteus

    Safety issues Although M. luteus is non-pathogenic and usually regarded as a contaminant, it should be considered as an emerging nosocomial pathogen in immunocompromised patients. 4 The bacteria should not be exposed to people. A lab coat and glasses should be worn to avoid the bacteria getting into the eye or on the skin.

  2. Ecology Open Investigation Does the geographic location affect the biotic and abiotic ...

    water thus the more accurate results are Each group should attach the Horiba equipment to a ruler. Attach the top of the Horiba to the end of a 30cm ruler - this will allow the sample to be collected at deeper waters.

  • Over 160,000 pieces
    of student written work
  • Annotated by
    experienced teachers
  • Ideas and feedback to
    improve your own work