• Rotates 360 degrees
• functions in motility of cell through environment

• Rigid tubular structure made of pilin protein
• Found only in gram-negative cells
• Function to join bacterial cells for partial DNA transfer called conjugation

Slime layer - loosely organized and attached

Capsule - highly organized, tightly attached

Has a thick homogeneous sheath of peptidoglycan

- 20-80 nm thick

Outermost layer contains lipopolysaccharides and lipoproteins (LPS)

• Lipid portion (endotoxin)may become toxic when released during infections
• May function as receptors and blocking immune response
• Contain porin proteins in upper layer - regulate molecules entering and leaving cell

Bottom layer is a thin sheet of peptidoglycan

• Periplasmic space above and below peptidoglycan

Lipopolysaccharide

The LPS of gram-negative baceria is an endotoxin with generalized pathologic effects such as fever

Peptidoglycan, Teichoic acid, Lipoteichoic acid, Mycolic acids and polysaccharides

Nontypical Cell Wall

• Several bacterial groups lack the cell wall structure of gram(+) or gram(-) bacteria

For example, cells of Mycobacterium and Nocardia have peptioglycan, but most of their cell wall is composed of unique lipids (e.g., mycolic acid which contributes to pathogenicity)

Such lipids can give the cell wall a thick, waxy nature with a high degree of resistance to certain chemicals and dyes.  Such resistance is basis for acid-fast stain used for diagnosis of infections caused by these microorganisms.

For example, Mycoplasma

Cell membrane is stabilized by sterols (alcohols)

These bacteria are extremely varied in shape (pleomorphic).  Pleomorphic means they can change their shape.

• Providing site for energy reactions, nutrient processing, and synthesis
• Passage of nutrients into the cell and the discharge of wastes. (Cell membrane is selectively permeable)

• Dense gelatinous solution of sugars, amino acids, and salts
• 70-80% water (serves as solvent for materials used in all cell functions)
• Components of this pool serve as building blocks for cell sythesis or as sources of energy

• Single, circular, double-stranded DNA molecule that contains all the genetic information required by a cell
• Aggregated in a dense aea call the nucleoid (not enclosed, DNA is tightly coiled)
• When exposed to special stains or observed with an electron microscope, chromosomes have a granular or fibrous appearance.

• small circular, double-stranded DNA
• Free or integrated into the chromosome
• Duplicated and passed on to offspring
• Not essential to bacterial growth and metabolism
• May encode antibiotic resistance, tolerance to toxic metals, enzymes, and toxins
• Used in genetic engineering - readily manipulated and trnasferred from cell to cell 

• Made of 60% ribosomal RNA and 40% protein
• Consist of two subunits: large and small
• Prokaryotic differ from eukaryotic in size and number of proteins
• site of protein synthesis
• Present in all cells

• Intracellular storage bodies
• Vary in size, number, and content
• Bacterial cell can use them when environmental sources are delpleted
• Examples: glycogen poly B-hydroxybutyrate, gas vesicles for floating, sulfur and phosphate granules (metachromatic granules), particles of iron oxide

Inert, resting (dormant),cells produced by the bacteria:

ex: Clostridium, Bacillus, and Sporosarcina

Vegaetative Cell - metabolically active and growing

Endospore - when exposed to adverse environmental conditions; capable of high resistance and very long-term survival

Sporulation

(This is not a means of reproduction)

• resistance linked to high levels of calcium and dipicolinic acid
• dehydrated, metabolically inactive
• thick coat
• longevity verges on immortatlity, 250 million years
• resistant to ordinary cleaning methods and boiling
• Pressurized steam at 120 C for 20-30 will destroy

in pairs

Diplobacilli - pairs

chains

palisades (kind of like the chain of hearts you would draw as a child)