1. Functional Anatomy of Prokaryotic
and Eukaryotic Cells

2. • Prokaryote comes from the Greek words
for prenucleus
• Eukaryote comes from the Greek words
for true nucleus.

3. Prokaryote Eukaryote
• One circular • Paired
chromosome, chromosomes,
not in a in nuclear
membrane membrane
• No histones • Histones
• No organelles • Organelles
• Peptidoglycan • Polysaccharide
cell walls cell walls
• Binary fission • Mitotic spindle

4. Prokaryote
• One circular chromosome,
not in a membrane
• No histones
• No organelles
• Peptidoglycan cell walls
• Binary fission

5. Eukaryote
• Paired chromosomes, in nuclear membrane
• Histones
• Organelles
• Polysaccharide cell walls
• Mitotic spindle

6. Prokaryote
• Average size: 0.2 -1.0 µm 2 - 8 µm
• Basic shapes

7. Arrangements
• Coccus – “ Berry”, round, oval

8. 2. Bacilli – Diplobacilli, Streptobacilli, Coccobacilli

9. 3. Spirals / Spirochetes – have 1 or more twist

10. Structures External to the Cell wall
• 1. Glycocalyx
• 2. Flagella
• 3. Axial Filaments
• 4. Fimbria
• 5 Pilus

11. Glycocalyx
• Outside the cell wall
• Usually sticky
2 types:
1. Capsule - neatly organized
2. Slime Layer - unorganized & loose
• Extracellular polysaccharide allows cell to attach
• Capsules prevent phagocytosis ( Virulence Factor)
•

12. Flagella
• Outside cell wall, for Locomotion
• Made of chains of flagellin
• Attached to a protein hook

14. Axial Filaments
• Endoflagella, For Locomotion
• In spirochetes ( Treponema pallidum)
• Anchored at one end of a cell
• Rotation causes cell to move

15. Fimbria & Pilus
• Fimbriae - allow attachment (Neisseria
gonorrhea)
- hairlike, short
• Pili - used to transfer DNA from one cell to
another ( Sex pili)

16. Cell Wall
• Complex, Semi-rigid structure
1. Protects the interior of the cell (prevents
osmotic lysis)
2. Maintains the shape
3. Point of anchorage of Flagella
Made of peptidoglycan (in bacteria), Virulence
Factor

17. Peptidoglycan
- Polymer of disaccharide
N-acetylglucosamine (NAG) & N-acetylmuramic
acid (NAM)
- Linked by polypeptides

19. Gram-Positive cell walls
• Thick peptidoglycan
• Teichoic acids
• In acid-fast cells, contains mycolic acid
• May regulate movement of cations
• Polysaccharides provide antigenic variation

20. Gram-Negative Outer Membrane
• Thin peptidoglycan
• No teichoic acids
• Outer membrane
• Lipopolysaccharides, lipoproteins, phospholipids
• Protection from phagocytes, complement,
antibiotics

21. Gram Stain Mechanism
Crystal violet-iodine crystals form in cell
Gram-positive
- Alcohol dehydrates peptidoglycan
- CV-I crystals do not leave
Gram-negative
- Alcohol dissolves outer membrane and leaves
holes in peptidoglycan
- CV-I washes out

22. Structures Internal to the Cell Wall
• 1. Plasma Membrane
• 2. Cytoplasm
• 3. Nuclear area
• 4. Ribosomes
• 5. Inclusion bodies
• 6. Endospores

23. Plasma Membrane / Cytoplasmic
Membrane

24. • Phospholipid bilayer
• Peripheral proteins
• Integral proteins
• Transmembrane proteins

25. • Selective permeability allows passage of some
molecules
Large molecules – inhibited
Small molecules – allowed to pass
- H+, O, Lipid soluble
• Damage to the membrane by alcohols,
quaternary ammonium (detergents) and
polymyxin antibiotics causes leakage of cell
contents.

26. Movement Across Membranes
• Simple diffusion – Movement of a solute from
an area of high concentration
to an area of low
concentration.
• Facilitative diffusion - Solute combines with a
transporter protein in the
membrane.

28. • Osmosis
Movement of water across a selectively
permeable membrane from an area of high
water concentration to an area of lower water
Osmotic pressure
The pressure needed to stop the movement of
water across the membrane.

30. Cytoplasm
• Cytoplasm is the substance inside the plasma
membrane
- 80% water, proteins, CHON, Lipids
inorganic ions
- where the nuclear area, ribosomes
& ribosomes are found.

31. Nuclear Area
• Stores the bacterial genetic information.
• No nuclear envelope
• Attached to plasma membrane
• Bacterial Chromosomes
- single, long, continuously arranged double
stranded DNA.
• Plasmid
- small, circular double stranded DNA
separate from chromosomal DNA capable
of replicating

32. • Function of Plasmids:
1. Genes for antibiotic resistance
2. Tolerance to toxic metals
3. Production of toxins
4. Synthesis of enzymes

33. Ribosomes
• Circular, Site of protein synthesis
• Site for antibiotic attachment

34. Inclusions
• Metachromatic granules
• Polysaccharide granules
• Lipid inclusions
• Sulfur granules
• Magnetosomes

35. Endospores
• Resting cells, formed when essential nutrients
are depleted
• Resistant to desiccation, heat, chemicals
• Bacillus, Clostridium
• Sporulation: Endospore formation
• Germination: Return to vegetative state

36. Eukaryotic Cells

37. Flagella and Cilia

38. Cell Wall
• Cell wall
Plants, algae, fungi
Carbohydrates
• Cellulose, chitin, glucan, mannan
• Glycocalyx
Carbohydrates extending from animal
plasma membrane
Bonded to proteins and lipids in membrane
No Peptidoglycan

39. Plasma Membrane
• Phospholipid bilayer
• Peripheral proteins
• Integral proteins
• Transmembrane proteins
• Sterols
• Glycocalyx carbohydrates
• Selective permeability allows passage of some
molecules
• Simple diffusion
• Facilitative diffusion
• Osmosis
• Active transport

40. • Endocytosis
• Phagocytosis: Pseudopods extend and engulf
particles
• Pinocytosis: Membrane folds inward bringing in
fluid and dissolved substances

41. Organelles
• Membrane-bound:
• Nucleus Contains chromosomes
• ER Transport network
• Golgi complex Membrane formation and
secretion
• Lysosome Digestive enzymes
• Vacuole Brings food into cells/stores
• Mitochondrion Cellular respiration
• Chloroplast Photosynthesis
• Peroxisome Oxidation of fatty acids;
destroys H2O2

42. Nucleus

43. Endoplasmic Reticulum

44. Golgi Complex

45. Lysosomes

46. Mitochondrion

47. Chloroplast