Topic 1 - Microscopy Flashcards
What is the primary purpose of microscopes?
To enlarge the image of extremely small structures such as cells
Microscopes are essential for observing structures that are not visible to the naked eye.
Who first observed cells in cork and in what year?
Robert Hooke in 1665
Hooke’s observations were made using a light microscope.
What are the main components of a light microscope?
Two lenses and illumination from underneath
Light microscopes typically provide a maximum magnification of 2000x.
What is the maximum resolving power of a light microscope?
200nm
Resolving power affects the ability to distinguish between two points.
What types of structures can be viewed with a light microscope?
Tissues, cells, and large sub-cellular structures
Light microscopes are commonly used in biological studies.
What significant advancement in microscopy occurred in the 1930s?
The development of the electron microscope
This allowed for viewing deep inside sub-cellular structures.
What is used to form images in an electron microscope?
Electrons
Electrons have a much smaller wavelength than light waves, enabling higher resolution.
What are the two types of electron microscopes?
Scanning electron microscope (SEM) and transmission electron microscope (TEM)
SEM creates 3D images, while TEM creates 2D images detailing organelles.
What is the maximum magnification of a scanning electron microscope?
Up to 2,000,000x
SEM provides slightly lower magnification compared to TEM.
What is the resolving power of a transmission electron microscope?
0.2nm
This allows for very detailed imaging of organelles.
What small structures have become clearer due to the use of electron microscopes?
Ribosomes and viruses
TEMs have been particularly useful in discovering viruses like poliovirus and smallpox.
True or False: Electron microscopes can identify viruses better than light microscopes.
True
Viruses are much smaller than bacteria and very hard to identify using standard light microscopes.
Fill in the blank: Electron microscopes allow examination of _______ in much greater detail than light microscopes.
proteins
This has led to many important scientific discoveries.
What is the eyepiece in a light microscope?
The part of microscope that we look through to view specimens.
The eyepiece is an essential component for observing the specimen.
What is the function of the barrel in a light microscope?
The upper part of the microscope that can be moved up or down to focus the image.
Adjusting the barrel helps achieve a clear view of the specimen.
