About Structure of Bacteria PowerPoint Presentation

Slide 1 -

Structure of Bacteria

Slide 2 -

Chapter 4 Size of Bacteria Average bacteria 0.5 - 2.0 um in diam. RBC is 7.5 um in diam. Surface Area ~12 um^2 Volume is ~4 um Surface Area to Volume is 3:1 Typical Eukaryote Cell SA/Vol is 0.3:1 Food enters through SA, quickly reaches all parts of bacteria Eukaroytes need structures & organelles

Slide 3 -

Chapter 4 Shapes of Bacteria Coccus Chain = Streptoccus Cluster = Staphylococcus Bacillus Chain = Streptobacillus Coccobacillus Vibrio = curved Spirillum Spirochete Square Star

Slide 4 -

Chapter 4

Slide 5 -

Chapter 4

Slide 6 -

Chapter 4

Slide 7 -

Chapter 4

Slide 8 -

Chapter 4

Slide 9 -

Chapter 4 Bacterial Structures Flagella Pili Capsule Plasma Membrane Cytoplasm Cell Wall Lipopolysaccharides Teichoic Acids Inclusions Spores

Slide 10 -

Chapter 4 Flagella Motility - movement Swarming occurs with some bacteria Spread across Petri Dish Proteus species most evident Arrangement basis for classification Monotrichous; 1 flagella Lophotrichous; tuft at one end Amphitrichous; both ends Peritrichous; all around bacteria Observe Picture in Micro Lab.

Slide 11 -

Chapter 4

Slide 12 -

Chapter 4 Mono- or Lophotrichorus

Slide 13 -

Chapter 4

Slide 14 -

Chapter 4 Pili Short protein appendages smaller than flagella Adhere bacteria to surfaces E. coli has numerous types K88, K99, F41, etc. Antibodies to will block adherance F-pilus; used in conjugation Exchange of genetic information Flotation; increase boyancy Pellicle (scum on water) More oxygen on surface

Slide 15 -

Chapter 4 F-Pilus for Conjugation

Slide 16 -

Chapter 4 Capsule or Slime Layer Glycocalyx - Polysaccharide on external surface Adhere bacteria to surface S. mutans and enamel of teeth Prevents Phagocytosis Complement can’t penetrate sugars

Slide 17 -

Chapter 4 Cytoplasm 80% Water {20% Salts-Proteins) Osmotic Shock important DNA is circular, Haploid Advantages of 1N DNA over 2N DNA More efficient; grows quicker Mutations allow adaptation to environment quicker Plasmids; extra circular DNA Antibiotic Resistance No organelles (Mitochondria, Golgi, etc.)

Slide 18 -

Chapter 4 Cell Membrane Bilayer Phospholipid Water can penetrate Flexible Not strong, ruptures easily Osmotic Pressure created by cytoplasm

Slide 19 -

Chapter 4

Slide 20 -

Chapter 4

Slide 21 -

Chapter 4

Slide 22 -

Chapter 4 Cell Wall Peptido-glycan Polymer (amino acids + sugars) Unique to bacteria Sugars; NAG & NAM N-acetylglucosamine N-acetymuramic acid D form of Amino acids used not L form Hard to break down D form Amino acids cross link NAG & NAM

Slide 23 -

Chapter 4

Slide 24 -

Chapter 4

Slide 25 -

Chapter 4

Slide 26 -

Chapter 4

Slide 27 -

Chapter 4

Slide 28 -

Chapter 4

Slide 29 -

Chapter 4 Cell Wall Summary Determine shape of bacteria Strength prevents osmotic rupture 20-40% of bacteria Unique to bacteria Some antibiotics effect directly Penicillin

Slide 30 -

Chapter 4 Video Clip on Cell Wall

Slide 31 -

Chapter 4 Teichoic Acids Gram + only Glycerol, Phosphates, & Ribitol Attachment for Phages

Slide 32 -

Chapter 4

Slide 33 -

Chapter 4 Lipopolysaccharide (LPS) Endotoxin or Pyrogen Fever causing Toxin nomenclature Endo- part of bacteria Exo- excreted into environment Structure Lipid A Polysaccharide O Antigen of E. coli, Salmonella G- bacteria only Alcohol/Acetone removes

Slide 34 -

Chapter 4

Slide 35 -

Chapter 4

Slide 36 -

Chapter 4 LPS (cont’d) Functions Toxic; kills mice, pigs, humans G- septicemia; death due to LPS Pyrogen; causes fever DPT vaccination always causes fevers Adjuvant; stimulates immunity Heat Resistant; hard to remove Detection (all topical & IV products) Rabbits (measure fever) Horse shoe crab (Amoebocytes Lyse in presence of LPS)

Slide 37 -

Chapter 4 LPS (cont’d.) Appearance of Colonies Mucoid = Smooth (lots of LPS or capsule) Dry = Rough (little LPS or capsule) O Antigen of Salmonella and E. coli 2,000 different O Ags of Salmonella 100’s different O Ags of E. coli E. coli O157 O Ags differ in Sugars, not Lipid A

Slide 38 -

Chapter 4 Endospores Resistant structure Heat, irradiation, cold Boiling >1 hr still viable Takes time and energy to make spores Location important in classification Central, Subterminal, Terminal Bacillus stearothermophilus -spores Used for quality control of heat sterilization equipment Bacillus anthracis - spores Used in biological warfare

Slide 39 -

Chapter 4

Slide 40 -

Chapter 4

Slide 41 -

Chapter 4 G+ vs. G- G+ Thicker cell wall Teichoic Acids G- Endotoxin - LPS Which are more sensitive to Penicllin? Alcohol/Acetone affects which more?

Slide 42 -

Chapter 4 Prokaryotes vs. Eukaryotes Cell Wall Teichoic Acids LPS Endospores Circular DNA Plasmids

Slide 43 -

Chapter 4 Eukaryote Cell Structure