2.1.3 Microscopy Flashcards
Define magnification
How many times bigger an object appears
Define resolution
The ability to distinguish two points next to each other
If the resolution of a microscopic image is too low, what can be said about the light/electrons used
The wavelength is too long
Magnification equation
Magnification = image size / actual size
1cm = ?mm
10
1mm = ?µm
1000
1µm = ?nm
1000
Measurement unit conversion image
How to measure an object using a microscope and graticule
- Line up graticule with object
- Count how many epu for the measurement
- Calibrate graticule using stage micrometer - how many µm per epu
- Multiply the number of epu by the calibration factor
Resolution of optical microscope
Low
Resolution of SEM
Medium
Resolution of TEM and ADVANTAGE
- High
- Allows organelles to be seen in greater detail
Magnification of optical microscope
Low
Magnification of TEM
High
Magnification of SEM
Medium
How does a optical microscope work
Light ray focused onto object then onto eye using glass lenses
How does a SEM work
- Electrons deflected/bounce off specimen
- Foccused by electromagnets
How does a TEM work
- Electrons transmitted/pass through specimen
- Foccused by electromagnets
Primary use of optical microscope
Study living cells
Primary use of SEM
View 3D image
Primary use of TEM
View cell ultrastructure
Are optical microscope images in colour
Yes
Are TEM images in colour
No
Are SEM images in colour
No