3. Analysis of Cell Components Flashcards
When were cells first seen and who by?
In 1665 by Robert Hooke.
They were studied in more detail by Leeuwehoek using a primitive microscope.
What is magnification?
Is how much bigger the image is that than the original object.
Its given as a magnification factor.
Using more lenses microscopes can magnify a larger mount but the image may get blurred- less detail seen.
What is the formula for magnification?
Magnification = Size of image divided by size of real object.
What is resolution?
Its how detailed the image is.
How well the microscope distinguished between 2 points that are close together.
If microscope can’t separate out 2 images then increasing magnification won’t help.
How can you improve the resolution of a microscope?
A shorter wave length of light is needed.
Microscopes sometimes have blue filters for this purpose.
Blue has shortest wavelength of visible light.
What can a microscope not distinguish between?
Objects that are smaller than its maximum resolution.
Name the types of microscope?
Transmission.
Fluorescence.
Interference.
Confocal.
What are transmission Microscopes?
Most common kind.
Light is transmitted through the specimen.
Resolution of about 200nm which is good enough to see tissues and cells, but not details of organelles.
What are fluorescence microscopes?
Fluorescent dye to stain specimens.
Specimen is illumined with invisible ultraviolet radiation, and the stained objects emit visible light, they can be seen even if the object is smaller than the wavelength of light.
Resolution of about 10nm.
What are Interference microscope?
Use the interference pattern produced by combining 2 light beams that have passed through different objects to produce an image.
Resolution of about 1nm.
What are confocal microscopes?
Use lasers to scan a thin layer of thick specimen.
By combining scan of different layers of computer, a three dimensional image can be built up.
