Prokaryotes, Eukaryotes and

VirusesAre they all living?

Living Cells• All living organisms are

made up of two basic types of cells– Prokaryotic cells are

bacterial cells– Eukaryotic cells are plant

and animal cells

The Cell Theory• All living organisms are made

of cells• All cells come from pre-

existing cells• Cells are the basic unit of life

Prokaryotes

Bacterial cells

A bacterium:

•contains 0.001 times less DNA than Eukaryotes

•is surrounded by a membrane and cell wall

•lacks membrane-bound organelles

• Cyanobacteria - “blue-green algae” are bacteria that contain chloroplasts for photosynthesis

EukaryotesPlant and animal cells

• Plasma membrane• Cell wall in plant cells only• Cytoplasm (semifluid)

• Cytoskeleton (suspend organelles and give shape) cyto=cell

• Contains membrane bound organelles

Viruses• Are they a type of cell?• No! Viruses are just genetic

information surrounded by a protein coat

Bacteriophage – a virus that infects bacteria

• Viruses can’t reproduce on their own

• They need a host cell to “infect”

PLANT CELL

ANIMAL CELL BACTERIAL CELL

VIRUS