Prokaryotic cells have a simple structure with DNA and other cellular components floating freely in the cytoplasm and no organelles, while eukaryotic cells have a compartmentalized structure with membrane-bound organelles. Both cell types contain DNA, ribosomes, and cytoplasm but prokaryotes have cell walls and looped DNA while eukaryotes have histone-bound DNA in chromosomes. Electron microscopes are used to view cellular ultrastructure at higher resolution than light microscopes.

1. ULTRASTRUCTURE OF CELLS
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2. PROKARYOTIC CELL
•Single-celled prokaryotic cells have a very simple structure
•All the DNA and other chemicals of life float freely in the cytoplasm: there are no organelles
•There is no compartmentalisation
•They divide by binary fission

3. DRAWING PROKARYOTES
•Example:
•The most important elements are: cell wall, pili and flagella, plasma membrane, cytoplasm, 70S ribosomes and naked loop of DNA

4. EUKARYOTIC CELLS
•Eukaryotic cells have a compartmentalised structure, with membrane- bound organelles
•They often join together to form multicellular organisms
•Eukaryotes are usually larger than prokaryotes

5. DRAWING EUKARYOTES
•Example:
•The most important elements are: plasma membrane, cytoplasm, 80S ribosomes, nucleus, mitochondria, some other organelles

6. PROKARYOTES VS. EUKARYOTES
•Both have: cell membranes, DNA, ribosomes, metabolism, and cytoplasm
•Differences include: prokaryotes have cell walls (and eukaryotic plant cells), eukaryotes have histone-bound DNA, prokaryotic DNA is in a single loop, eukaryotic DNA is found in chromosomes

7. ELECTRON MICROSCOPES
•Electron microscopes have much higher resolution than light microscopes
•They are used to take images of the ultrastructure of cells