1. Topic 2.2 Prokaryotic Cells

2. Assessment Statements:
2.2.1 Draw and label a diagram of the ultrastructure of Escherichia coli (E. coli) as an example of a prokaryote
2.2.2 Annotate the diagram from with the functions of each named structure.
2.2.3 Identify structures from in electron micrographs of E. coli
2.2.4 State that prokaryotic cells divide by binary fission

3. Introduction to Prokaryotes

4. Prokaryotic Cell Structure

6. Annotate the diagram

7. Cell Membrane Controls passage of materials into and out of the cell
All cells have a cell membrane

8. Cytoplasm
Fluid portion of all cells
Location of cellular metabolism

9. Ribosomes Float freely in the cytoplasm of all cells
Smaller in prokaryotes (70s)
The site of protein synthesis.

10. Nucleoid The glob of DNA in all prokaryotic cells Still a double helix
Ends come together to form a circle
Not wrapped around proteins as in eukaryotic cells (termed “naked DNA”).

11. Prokaryote vs. Eukaryote Chromosome
DNA double helix
Eukaryote

12. Plasmid
A small circle of DNA found in some prokaryotes that exists and replicates independently of the main DNA in the nucleoid.
Often contain genetic instructions for resistance to antibiotics (antibiotics are chemicals that kill bacteria)

13. Some Prokaryotes have a cell wall
Gives shape, support and protection to the plasma membrane and cytoplasm of the cell.
Eubacteria wall made of peptidoglycan* (protein-sugar molecules).
(* plant cell walls are made of cellulose)

14. Flagellum (flagella)
Some bacteria have one or more
Used for motility.

15. Pili
Short fibers projecting from the cell wall found on some bacteria.
They may help the bacteria cling to surfaces.

16. Capsule (or slime layer)
A special mucus-like protective coating found on some disease-producing bacteria.

17. Prokaryotic cells do not have membrane bound organelles

18. Reproduction in Prokaryotes

19. Binary Fission

20. Reproduction in Prokaryotes
Prokaryotes reproduce by binary fission “division in half”
Type of asexual reproduction
The cell replicates its genetic material
The cytoplasm divides by cytokinesis
Two identical daughter cells are produced (unless mutation occurs)

21. Review

22. Something interesting to finish...