Developments in Microscopy

• Developments in microscopy (use of the microscope) have allowed us to see smaller details inside cells. This has improved our understanding of cell functions.
• Light microscope

  • A light microscope passes light through a specimen and creates a magnified image using lenses.
  • The first light microscope was made using two lenses towards the end of the 16th century. This microscope had a resolution better than the human eye.
• Discoveries using light microscopes

  • Light microscopes allowed bacteria to be seen for the first time. They also allowed us to see plant cells and animal cells as separate objects.
  • However, we still could not tell lots of sub-cellular (within the cell) structures apart.
• Electron microscope

  • The electron microscope was first used in 1933.
  • Electron microscopes work in a similar way to light microscopes. However, electrons are passed through the specimen instead of light.
  • They can now resolve distances of 1nm (better resolution) with magnifications of ×500,000.
• Discoveries using electron microscopes

  • The high level of detail of electron microscopes allowed scientists to see sub-cellular structures more clearly.
  • They also allowed scientists to study how structures such as mitochondria, chloroplasts and ribosomes function.
• The electron microscope was first used in 1933