Prokaryotic cells are muchsmallerthan eukaryotic cells (between 100 - 1000 times smaller) so normal microscopes aren't really powerful enough to look at their internal structure.
Prokaryotic cells also differ from eukaryotic cells in having:
A cytoplasm that lacks membrane-bound organelles
Their ribosomes are structurally smaller (70 S) in comparison to those found in eukaryotic cells (80 S)
No nucleus (instead they have a single circular DNA molecule that is free in the cytoplasm and is not associated with proteins)
A cell wall that contains murein (a glycoprotein)
Prokaryotes vs Eukaryotes similarities
-plasma membrane
-cytoplasm
-ribosome for assembling amino acids into proteins
-DNA and RNA
Prokaryotes vs Eukaryotes differences
-DNA in nucleus in Eukaryotes
-no nucleus in Prokaryotes
-much less well-developed cytoskeleton with no centrioles in Prokaryotes
Some prokaryotic cells also have:
a protective waxy capsule
small loops of DNA (plasmids)
flagella
pili
Flagella
-a long, tail like structure which rotates to move the cell(some prokaryotes have more than one)-not present in all prokaryotes
Found in specialised cells
Similar in structure to cilia, made of longermicrotubules
microtubules contract to provide cell movement for example in sperm cells
Plasmid
-smallloops of DNAthat are separate from the main circular DNA molecule-not present in all prokaryotes
Plasmids containgenesthat can be passed between prokaryotes (e.g. genes forantibiotic resistance)
Capsule
-Some prokaryotes (e.g. bacteria) are surrounded by a final outer layer known as a capsule. This is sometimes called the slime capsule.-not present in all prokaryotes
It helps to protectbacteria from drying out and from attack by cells of the immune system of the host organism
Pili
-hair-like structures which attach to other cells or surfaces; involved in sexual reproduction