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• How the electron microscope works

  1. Electron beam

  2. Specimen

  3. Fluorescent screen must be in the vacuum

  4. Electron gun and anode emit high velocity electron beam

  5. Condenser electromagnetic lens focuses the electron beam onto the specimen

  6. Objective electromagnetic lens focuses and magnifies the first image

  7. Projector electromagnetic lenses focus the magnified image onto the screen
• Transmission electron microscope (TEM)


  Pathway of electrons
• Scanning electron microscope (SEM)


  Pathway of electrons
• Comparison of light and electron microscopes

  • Light Microscope: Uses light as a source of radiation, Images projected on the eye or on photographic film, Preparation of specimen simple, Magnifies up to 2000X, Either dead or alive specimen can be examined, Inexpensive to purchase and operate
  • Electron Microscope: Uses electron as a source of radiation, Image projected on a screen or on photographic film, Preparation of specimen lengthy and complicated, Magnifies up to 500,000X, Only dehydrated and dead specimen can be examined, Expensive to purchase and operate
• Magnification


  The ability to increase the size of the image of the object being studied so that microscopic organisms become visible
• Formula for Magnification

  Magnification = Observed size of the object / Actual size
• Resolution


  The ability to distinguish between two objects that are close together
• An increase in magnification does not always produce a more detailed image
• With resolution, the greater the resolution, the greater the detail
• Biotechnology


  A branch of applied biology which combines biological sciences with engineering technologies
• Biotechnology


  • Applies the use of living systems and organisms to produce useful chemicals and products or to carry out industrial work for mankind
• Traditional Biotechnology


  • Making wine, cheese, yoghurt, bread and beer
• Traditional biotechnology came into use thousands of years ago when people unknowingly discovered the usefulness of microorganisms like bacteria and yeast
• Enzyme biotechnology


  Producing biological washing powder and fruit juice
• Biology is the Science of Life
• Biology is the study of living things, such as plants, animals and microorganisms
• People's lack of understanding of biology


  Disturbing the balance of nature
• The world is suffering under the impact of infectious disease outbreak and weather changes caused by the effect of global warming
• Over fishing, over hunting and deforestation may lead to problems in feeding the world's exploding population
• Many species of plants and animals have disappeared forever
• If people have more knowledge on biology and understanding of nature


  This would never have happened
• Nature will give back what it is given to it
• Fields where biology is important

  • Animal breeding
  • Agriculture
  • Medicine
• Knowledge of biology will help mankind to protect nature, feed the starving nation and leave the world a better place for our future generations
• Pure science


  Studies the basic facts or principles, such as the study of structure and function of living things
• Pure science branches

  • Morphology (study of structure and form of organisms)
  • Cytology (study of cell structure and function)
• Applied science


  Concerned with applying the basic knowledge to practical application or particular technologies
• Applied biology branches


  • Biotechnology (application of biology)