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

The electron microscope and biological advancement.

Extracts from this document...


Toby Nicholson

The electron microscope and biological advancement

What is an electron microscope?

        An electron microscope does a similar job to an ordinary optical microscope that many people will have used before - it makes objects appear bigger. This is called magnification and lets one see details of very small objects, such as cell structures, which cannot be seen with the naked eye. In a normal optical microscope this is achieved by using higher-power lens that magnify the image more times.

However, there comes a point at which magnification of an optical microscope does not show more detail. This is to do with the physical nature of light. Light is made up of particles (called photons) that travel in a wave. We can only see that two objects are separate if light can pass between them. Light can pass between the letters on this page so you can see them. When objects are very close together light cannot pass through them and they appear as one object.

...read more.


The surface features of an object or "how it looks", its texture. There is a direct relation between these features and materials properties (hardness, reflectivity...etc.)

  • Morphology

The shape and size of the particles making up the object. This relates between their structures and materials properties (ductility, strength, reactivity...etc.) image02.png

  • Composition

The elements and compounds that the object is composed of and the relative amounts of them; direct relationship between composition and materials properties (melting point, reactivity, hardness...etc.)

  • Crystallographic Information

How the atoms are arranged in the object. We can deduce from this a relation between these arrangements and materials properties (conductivity, electrical properties, strength...etc.)

(www.unl.edu/CMRAcfem/em.htm, 13/10/02, University of Nebraska Lincoln)

        It is clear to seen the advantage of the electron microscope with the comparison of these two slidesimage03.pngimage04.png

What have electron microscopes done for biology?

Although the electron microscope has advanced many different areas of science, the particular area biology that has been most helped has been the understanding of cell ultra structure or microbiology.

...read more.



        In conclusion the electron microscope is a huge leap forward is microscopy as it has a mush larger resolving power, this has aided microbiologists greatly allowing them to see cell ultra structure as well as viruses and even analyse DNA. The principal part of what is known about cell ultra structure is thanks to the electron microscope. It allows for an understanding of all things small from insects, to bacteria, to DNA. I has also helped supported the theory of evolution and contributed to forensic science.


        Indge,B etal


        A New Introduction To Biology

        Hodder & Stoughton

        ISBN 0 304 78167X

        Iowa State University

mse.iastate.edu/microscopy/insects.html, 13/10/02

        University of Nebraska Lincoln

www.unl.edu/CMRAcfem/em.htm, 13/10/02

Roberts, B etal


Biology Principles and Processes

Thomas Nelson and Sons Ltd

ISBN 0-17-448176-4

Encyclopedia Britannica CD-ROM Deluxe Edition


 New York State Police Forensic Department

www.troopers.state.ny.us/ForSc/ModFor/E-Micro.html, 14/10/02

...read more.

This student written piece of work is one of many that can be found in our AS and A Level Microscopes & Lenses 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 AS and A Level Microscopes & Lenses essays

  1. Peer reviewed

    The Principles and Limitations of Electron Microscopy.

    3 star(s)

    Electron Microscopes were developed due to the limitations of Light Microscopes. A good light microscope can only magnify an object effectively about 1500 times. The Electron Microscope can give clear pictures that are magnified 500,000 times. It is important to appreciate how important this can be in practice: with the

  2. Telescopes - research into types and properties of telescopes

    Astronomers generally prefer reflecting telescopes to refracting telescopes. The weight of a large lens can cause it to bend and become distorted. But a large heavy mirror can be supported from behind. As a result mirrors can be made much larger than lenses, and therefore can gather more light.

  1. A brief history of how the light microscope has developed since the 17th Century ...

    Spencer made some outstanding optical equipment, and built himself an industry. His model was modified to little measures, and today's present day light microscope can magnify things up to 1250 times with ordinary light and 5000 times with blue light.

  2. The History, Development and Use of the Light and Electron Microscope.

    So, with Hooke's design the third lens improved the contrast and brightness of images and allowed closer viewing through the microscope. The modern microscope is still based on Hooke's design in which the three lenses are replaced by multi-lens and mirrors to improve the quality of the images.

  1. The eye.

    Animals with their eyes in the sides of their head can usually see all round. Advantage for prey animals More notes can be viewed at http://www.biology.demon.co.uk/Biology/ The Human Eye The human eye is wrapped in three layers of tissue: * the sclerotic coat * This tough layer creates the "white"

  2. My experiments focus is to obtain an accurate measurement for a specific lenss power.

    Second Graph: Power result: The plotted values have produced minimum, mean, and maximum gradients that are closer together than all of the previous experiments. They intercept the x axis at -6.65 D, -6.67 D and -6.72 D respectively. The average of these results turns out to be 6.69 D with an uncertainty of +/- 0.035.

  1. Explain how the electron microscope has affected our knowledge of cell form and structure

    Light microscopes can only be used if the magnification is under x1500 whereas an electron microscope can magnify images will above x1500. Electron microscopes have a resolution power of 2nm, light microscopes can only distinguish two objects apart if they are 2?m apart.

  2. The use of the electron microscope has advanced our understanding of cell biology further ...

    We see how microscopes have progressed to the level that we can now see 3D images of cells and microscopic organisms. Light Microscopes: Invented in the 18th century, the light microscope was the beginning of what we now use to view microscopic cells and organisms.

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