1.1.3 microscopy

• A light microscope passes light through a specimen and creates a magnified image using lenses
• Modern light microscopes have low (100x), medium (200x), and high (400x) magnification settings
• Electron microscopes work in a similar way to light microscopes, except electrons are passed through the specimen instead of light
• Light microscopes' resolution is 0.25 micrometers. We cannot tell subcellular structures apart very well
• Electron microscopes can resolve distances of 0.25 nanometers (better resolution) with magnifications of 500,000x
• Electron microscopes are better suited for seeing subcellular structures more clearly
• Electron micrographs - black and white images - were used to study how structures such as mitochondria, chloroplasts, and ribosomes, function.
• The electron microscope was first used in 1933
• Resolution - the ability to distinguish between two or more objects that are close together
• Magnification - tells us how many times larger an image obtained using a microscope is, relative to the real object
• Light microscopes were first used in the 16th century
• Light microscopes have resolution better than the human eye