Microscopy Flashcards
What does magnification mean
How much bigger the image is than the specimen
What does resolution mean
How detailed the image is (how well a microscope distinguishes between 2 points that are close together)
What is the formula for magnification
Magnification = size of image / size of real object
What are the 2 types of microscope
Optical (light) microscopes and electron microscopes
How do optical microscopes work
They use light to form an image
What is the maximum magnification of an optical microscope
X1500
How do electron microscopes work
They use electrons to form an image
What is the maximum magnification of an electron microscope
X1,500,000
What organelles can you see with an optical microscope?
- ribosomes
- endoplasmic reticulum
- lysosomes
What are the 2 types of electron microscope
Transmission and scanning
How do transmission electron microscopes work
- electromagnets shoots beam of electrons
- goes through specimen
- denser parts absorb more electrons
How do scanning electron microscopes work
- scans a beam of electrons across specimen
- knocks electrons off the specimen
- gathered in cathode ray tube to form image
What are 3 differences between transmission and scanning electron microscopes
Transmission
- high resolution
- only used on thin specimens
- can see internal structures of organelles
Scanning
- low resolution
- only used on thick specimens
- can turn up to be 3D
What does homogenisation mean
Breaking up the cells through vibrating the cells or grinding the cells up in a blender - MUST BE ICE COLD AND ISOTONIC
What does filtration mean (in cell fractionation)
Getting rid of the large cell debris or tissue debris by filtering the solution through a gauze
