1) They're extremely small cells - less than 2 micro-metres in diameter
2) They have circular DNA
3) They don't have a nucleus - the DNA is found freely in the cytoplasm
4) The cell wall is made of a polysaccharide BUT it is not cellulose (like plant cells) or chitin (fungi cells)
5) They contain few organelles and no mitochondria (plural)
6) They're ribosomes are quite small
E.g. E.coli bacterium
1) They're large cells - about 2-200 micro-metres in diameter.
2) They're DNA is linear.
3) They have a nucleus - the DNA is found inside the nucleus.
4) Animal cells have no cell wall, Plant cells have a cellulose cell wall and Fungi have chitin cell walls.
5) Eukaryotes contain many organelles including mitochondria.
6) The ribosomes in eukaryotic cells are significantly larger.
E.g. Human liver cell
Prokaryotic Cells - Bacteria
Bacterial cells are prokaryotic - they're roughly the tenth of the size of eukaryotic cells. This means that normal microscopes are not powerful enough to really look at the bacterias internal structure. Electron microscopes however can show enough detail to determine what is found in a bacteria cell. Bacteria cells contain:
1) Flagellum 2) DNA
3) Plasma membrane 4) Cell Wall - made from a polysaccharide
5) Ribosome 6) Plasmid - a ring of DNA