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9.7 Option- Pharmaceuticals: 4. Penicillin fights bacteria

Syllabus reference (October 2002 version)
4. When penicillin is introduced into the circulatory system it can assist the body in fighting bacteria Students learn to: Students:
Extract from Senior Science Stage 6 Syllabus (Amended October 2002) © Board of Studies, NSW.
[Edit: 12 May 11].

Prior Learning: Science Stages 4-5 Syllabus: Outcome 4.8 (content 4.8.3a and b),

Background: Before our current understanding of bacteria and diseases caused by them, people died regularly from simple infections. The discovery of penicillin and the people involved in this discovery and development to commercial production is a fascinating story.

gather, process and present information from secondary sources to trace the historical development of our understanding of disease caused by bacteria including the contributions of two of:

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identify different types of bacteria based on shape

Descriptions and diagrams of bacterial shapes can be found in junior and senior biology texts e.g Haire et al, Core Science Bk 3 p 55

and you can find information at Bacteria (external website) J Stein Carter, Clermont College, University of Cincinnati, 2011

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outline the structure of bacteria to identify

  • cell membrane
  • cell wall
  • cytoplasm

Bacterial Cell Structure (external website): Cells Alive, Quill Graphics, USA

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plan, choose equipment and resources for, analyse the risk, implement appropriate procedures for and perform a first-hand investigation to culture bacteria present in our surroundings and relate the growth rate to environmental conditions of temperature

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outline the process of reproduction in bacteria by fission

Information on cells and cell division can be found at Introduction to bacteria (external website) Science in the Real World, Microbes in Action, University of Missouri, St Louis, Missouri, USA.
Scroll down to Growth.

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gather, process and present information from secondary sources to identify the rate of reproduction of different bacteria

Useful information
The rate of reproduction of bacteria is demonstrated by their population growth curve.
Bacteria grow most rapidly in the exponential or logarithmic growth phase when their numbers double during each generation time.
Generation time or doubling time is the time between the formation of a new bacterium and its division into two new daughter cells. Generation time is a characteristic of the species of bacterium.

Information, graphics and real-time pictures of bacteria growing (external website). Cells Alive, James A Sullivan, Quill Graphics, USA.

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identify conditions that determine the rate of reproduction of bacteria and explain their effects

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gather, process and present information to discuss the circumstances surrounding the identification of the substance produced by the fungus, Penicillium notatum, which appeared to inhibit the growth of bacteria

This source gives a very full account of the discovery of penicillin (external website). Penicillin The Wonder Drug, Botany Department, University of Hawai’i at Manoa, USA.

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explain why penicillin only works on bacteria while they are reproducing by relating its effect to its action on the bacterial cell wall

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assess the concern that bacteria have become resistant to penicillin and discuss possible implications for the future use of penicillin

The problem of antibiotic resistance (external website) is described. Combating Antibiotic Resistance, USFDA.

Bacterial Resisitance to Antibiotics (external website)

Dr Peter Rutledge, an Australian scientist working on developing drugs to treat resistant infections spoke to NSW DET teachers in May, 2009. Click here (external website) then scroll down to his name and click on VIDEO to see his presentation on the Curriculum Directorate web site.

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gather, process and present information from secondary sources to identify other antibiotics, their source, their mode of action and the bacteria they affect

Information on these drugs and their mode of action (external website). Antibiotics: Antibacterial Agents, Kimball’s Biology Page, USA. This is a good site for better students.

Useful information
Other commonly used antibiotics are the sulfa drugs and the tetracyclines.

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