1. Chapter 4 Prokaryote Eukaryote
One circular chromosome, not enclosed in a membrane
No histones
No membrane-bound organelles
Paired chromosomes, enclosed in a nuclear membrane
Histones
Membrane-bound organelles

2. Prokaryote Eukaryote Peptidoglycan cell walls
Binary fission
Polysaccharide cell walls
Mitosis

3. Bacterial Shapes and Arrangements
Bacilli – rod shaped
Cocci – spherical shaped
Spiral – have one or more twists
Coccobacilli – intermediate between coccus and bacillus
Strepto- chain of cells (bacilli or cocci)
Staphylo- cluster of cells (cocci)

4. Some Representative Cocci

5. Some Representative Bacilli

6. Prokaryotic Cell Structures

7. Glycocalyx Outside cell wall
Composed of polysaccharide, protein, or both
Called or slime layer
Allows cell to attach to things
may prevent phagocytosis

8. Capsule
Streptococcus pneumoniae and bacillus anthracis are among many bacterial
types that may possess capsules.

9. Flagella Outside cell wall Anchored to the cell wall and membrane
Used for motility (i.e. chemotaxis)
Promotes spreading of microbe in the disease process

10. Flagella Arrangement

11. Axial Filaments In
Anchored at one end of a cell and spiral around the cell
Rotation causes cell to move

12. Fimbriae and Pili Hair-like structures Fimbriae allow attachment
Pili are used to transfer DNA from one cell to another

13. Cell Wall
Prevents osmotic lysis
Made of (in bacteria)

14. Peptidoglycan
Polymer of disaccharide
Linked by short polypeptides

15. Cell Wall Types layer of peptidoglycan layer of peptidoglycan
Gram-positive cell walls
layer of peptidoglycan
Acid-fast cell walls
contains
Gram-negative cell walls
layer of peptidoglycan
Contains an outer membrane

17. Gram-Negative Outer Membrane
Provides some protection from host immune system attack, and some antibiotics.
Contains Lipid A, an endotoxin derived from lipopolysaccharide (LPS)

18. Gram Staining of Bacterial Cells
Purpose: to distinguish Gram positive from Gram negative bacteria
Dyes/solutions used:
1. Crystal violet
2. Iodine (mordant)
3. Alcohol
4. Safranin (counter stain)
Gram-positive bacteria:
Alcohol does not remove CV/I = purple cells
Gram-negative bacteria:
Alcohol removes CV/I = pink cells

19. Plasma Membrane Functions
: allows passage of some molecules in and out of cell
Site of photosynthesis
Site of ATP production
Components
Membrane proteins
Integral
peripheral

20. Plasma Membrane

21. Fluid Mosaic Model Membrane is as viscous as olive oil.
Proteins move freely within phospholipids.
Enables their functioning.
Phospholipids also move.
Enables protein movement and promotes repair.

22. Movement Across Membranes
: Movement of a solute from an area of high concentration to an area of low concentration.
: Solute combines with a transporter protein in the membrane.
of substances requires a transporter protein and ATP.

23. Facilitated Diffusion

24. Movement Across Membranes
Osmosis
Movement of “water” across a selectively permeable membrane from an area of high water concentration to an area of lower water concentration.

25. With regard to solutes, cells live under certain environmental conditions. These are:
Hypertonic environment
Hypotonic environment
Isotonic environment

27. Prokaryotic Cell Structures
Cytoplasm is the substance inside the plasma membrane
Nucleoid (nuclear area): region of DNA
Ribosomes: organelles where proteins are made
Inclusions: granules that serve as storage sites for nutrients, enzymes and other substances.

28. Endospores “Resting” cells
Highly resistant to desiccation, heat, freezing, chemicals
Many Bacillus and Clostridium species form endospores
Bacillus anthracis – anthrax
Bacillus botulinum - botulism
Clostridium tetani - tetanus

29. Endospore Formation