1. Prokaryotic Cells

2. Prokaryotes VS. Eukaryotes
No nucleus
Not bound by a nuclear membrane
Usually contains one circular chromosome composed of DNA with proteins
Ex. bacteria
Nucleus present
Bound by a nuclear membrane
Contains one or more paired linear chromosomes
Ex. plants and animals

3. 1. 2. 3.

4. Prokaryote Classification
Once classified into Kingdom Monera
Lack of nucleus & membrane- bound organelles
Now divided into two domains:
Domain Bacteria (most common/affect humans)
Domain Archaea

5. a. Domain Bacteria Bacteria (Kingdom Eubacteria)
Found everywhere except in extreme environments
Have strong cell walls w/ peptidoglycan (sugars & amino acids)

6. Cocci (Spherical/Round)
Shape
Cocci (Spherical/Round)
Bacilli
(Rod-shaped)
Spirilli
(Spiral-shaped)

7. Arrangements of Cocci

8. Arrangements of Bacilli

9. Arrangements of Spirilli

10. Metabolism- How they obtain energy
a. Heterotrophs “other feeder”- can’t synthesize own food; take in organic nutrients from the environment or other organisms
Saprotrophs or saprobes- obtain energy by decomposing dead organisms
Sapro- latin means rotten or putrid; troph means nutrition

11. Metabolism- How they obtain energy
b. Photoautotroph “light self-feeder”-carry out photosynthesis ; uses inorganic molecules (CO2 and H2O) to create organic molecules for food
Ie. Cyanobacteria

12. Metabolism- how they obtain energy
c. Chemoautotrophs “Chemical self feeder”- break down/release inorganic compounds containing N or S in chemosynthesis
Ie. Nitrogen Fixing Bacteria

13. Prokaryote Structure Microscopic Unicellular Organelles
No Nucleus or nuclear membrane
Contains circular DNA- nucleoid
Has cytoplasm, cell membrane & cell wall
Has ribosomes
No mitochondria or chloroplasts
Ribosomes make proteins from amino acids

14. Size 1-10 micrometers long, 0.7-1.5 micrometers wide
Favorable surface area-to-volume ratio
Nutrients & other substances can diffuse to all parts of the cell easily
Small cells have a more favorable surface area to volume ratio than larger cells
1 micrometer= 1,000,000 of a meter

15. Chromosomes
Genes are found on a large, circular chromosome in the area called the nucleoid
Many prokaryotes also have a smaller piece of DNA called a plasmid
Where are chromosome found in the cell of a eukaryotic cell? In the nucleus. What do chromosomes do? DNA containing structure that carries genetic material from one generation to another.

16. Capsule Complex sugar layer around cell wall Capsule Function:
Prevents cell from drying out
Helps cell attach to surfaces
Shelters cell from White Blood cells (WBCs) & antibiotics
Capsule
Cell Wall
Cell
Membrane
Polysaccharides are polymeric carbohydrate structures, formed of repeating units (either mono- or di-saccharides) joined together by glycosidic bonds

17. Movement Some are stationary Some have flagella
Help bacteria move towards light, higher oxygen concentration, or chemicals to survive
Tail like structure, some bacteria have more than one flagella
Flagella

18. Pili Hair-like structures made of protein Function:
Helps cells attach to surfaces
Serves as a bridge between cells
Copies of plasmids can be sent across this bridge giving bacteria new genetic characteristics
Pili

19. b. Domain Archaea Live in extreme environments (called extremophiles)
Thermoacidophiles
Halophiles
Methanogens
Environment
Hot (above 80C), acidic (pH of 1-2)
Salty
Anaerobes (can’t live in presence of oxygen)
Environment Examples
Sulfur hot springs, ocean floor thermal vents, volcanoes
Great Salt Lake, Dead Sea
Sewage treatment plants, swamps, bogs, GI tract

20. Bacteria & Archaea Differences
Similarities
Differences
Different cell wall components
Bacteria have peptidoglycan
Archaea lack peptidoglycan
Different lipids in cell membrane
Different proteins & nucleic acid
Size
Prokaryotes
Have cell walls

21. Reproduction Binary Fission- asexual reproduction
Division of cell into two genetically identical cells
Model with play dough

22. (Chromosome replicates)
(Original chromosome and new copy separate)
(New plasma membrane and cell wall form)
(two identical cells)

23. Undergo Exponential Growth

28. Cell Walls Determines the bacteria’s shape
All bacterial cells have cell walls
Eubacteria- have peptidoglycan
Archae- lack peptidoglycan; different lipids
Dyes added to bacteria to identify two types:
w/ outer layer of lipid
w/o outer layer of lipid
Sugars and amino acids
Technique =
Gram Stain

29. Gram Stain Gram Positive Gram Negative
Large amount of peptidoglycan= dark purple
Called gram positive
W/ a lipid layer; less peptidoglycan= light pink
Called gram negative
Gram Positive
Gram Negative
Not used to classify archae bacteria; yields results quicker than growing bacteria in culture

30. Why does it matter?
lipopolysaccharide
Gram negative bacteria are protected against most antibiotics & chemicals by their outer cell wall. Only certain antibiotics can work against them.

31. Check Your Understanding!!