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Cell Ultrastructure and Microscopes, Electron microscopes - Coggle Diagram
Cell Ultrastructure and Microscopes
Type of microscope
Light microscope
Maximum resolution: 200nm
Cheap to purchase, cheap to operate small + portable simple + easy sample preparation
Material rarely distorted by preparation Vacuum is not required Natural colour of sample maintained
The active process of mitosis can be observed
Electron microscope
Expensive, large, specimen must be dead, extremely sensitive to vibration and external magnetic fields.
They have a much higher range of magnification (can detect smaller structures)
Max Resolution: 0.5nm
They have a much higher resolution (can provide clearer and more detailed images)
Specimens cannot be alive
Prokaryotic cell
No nucleus
Bacteria
Cell wall (peptidoglycan)
Cell membrane
Cytoplasm
Circular DNA
Ribosome (70S)
Additional features
plasmid
flagella
Pili
Capsule
No membrane bound organelles
Smaller than eukayotes
Binary fission for cell division
ONLY IN Plant cell
vacuole and tonoplast
surrounded by membrane called tonoplast (controls exchange between vacuole and cytoplasm) contains mineral salts, O2 and CO2
Cell wall
B-glucose --> 180 degree to adjacent molecules --> cross linked --> microfibril --> microfiber --> cellulose
Chloroplast
double membrane
thylakoid - flattened scas
cholorphyll
stacked --> grana --> linked by lamella
70S ribosome
circular DNA
Plasmodesmata ; pore-like structure --> allow a link between neighbouring cells by fine threads of cytoplasm.
Eukaryotic cell
Mitochondria
Nucleus
Has nuclear pores
Nucleolus
Ribosomes
ER
RER
SER
Golgi body
Cytoplasm
Cell membrane
Chloroplast
Centrioles
ONLY IN Animal
centrioles
9 triplets of microtubles
Centrosome
pair of centrioles at right angles --> act as MTOCs
involved in Mitosis
Electron
microscopes
TEM
electrons pass through thhe spcimen and only ones that re transmitted are seen
Can see thin section of the specimens (inside cells)
SEM
scan surfaces and only reflected beams are observed
Adv- surface structures can be ssen in 3 dimensions
Dis adv- different resolution 3nm-20nm
Maximum resolution: 0.5nm
Short wavelength: 0.005nm
Images: Black and white
Specimen has to be dead
Not able to observe mitosis