Transcript Prokaryotic vs. Eukaryotic Cells

Prokaryotic vs.
Eukaryotic Cells
Prokaryotic vs.
Eukaryotic Cells
• All cells fall into one of the two major
classifications of prokaryotes and eukaryotes.
Prokaryotes were here first and for billions of
years were the only form of life.
• Prokaryotes are unicellular organisms, found in all
environments. Prokaryotes are the largest group
of organisms, mostly due to the vast array of
bacteria which comprise the bulk of the
prokaryote classification.
Characteristics:
• No nuclear membrane (genetic material
dispersed throughout cytoplasm)
• No membrane-bound organelles
• Simple internal structure
• Most primitive type of cell (appeared
about four billion years ago)
Examples:
• Staphylococcus
• Escherichia coli (E. coli)
• Streptococcus
– Note that all of the above are different strains of
bacteria.
• Eukaryotes are generally more advanced than
prokaryotes. There are many unicellular organisms
which are eukaryotic, but all cells in multicellular
organisms are eukaryotic.
Prokaryotic vs.
Eukaryotic Cells
Characteristics:
• Nuclear membrane surrounding genetic
material
• Numerous membrane-bound organelles
• Complex internal structure
• Appeared approximately one billion years
ago
Examples:
• Paramecium
• Dinoflagellates
• sapiens (Humans)
Prokaryotic vs.
Eukaryotic Cells
• It is hypothesized that a primitive
bacterium once surrounded its food
after releasing its digestive enzymes.
The membrane folded inward and
pinched off, creating the first
digestive membrane-bound organelle.
And now it's storytime!
• Once upon a time (about one billion years ago), the first
eukaryotic cell came to be. There was a group of primitive
bacteria going about their business when along came a big
hungry phagocyte, who ate one of the bacterium.
– Mr. Phagocyte: Yum.Bacterium: Excuse me.Mr. Phagocyte:
What?
Bacterium: You know, why don't we join forces and I can help
you and you can help me and we can become a 'eukaryotic' cell?
Whaddaya say?
Mr. Phagocyte: OK. The little engulfed bacterium evolved and
became the mitochondria in present-day cells.
Obviously, they all lived happily ever after.
Prokaryotic vs.
Eukaryotic Cells
• Review
Assigned activities
• Read Pages 23-24 in McGraw Hill Ryerson
• Through an online search look up the
definition of the term symbiosis. Answer
the following Question:
– How is this term applicable to the development
of the Eukaryotic Cell?
Test YourSelf
• Review