1. Chapter 10 Key Terms
Bacteria Binary Fission Conjugation Transformation Parasitic Virus Bacteriophage Retrovirus Vaccination Pathogen Inflammation Antibody Antibiotic Coccus

2. Bacteria and Viruses: Microbiology Part I
Biology Chapter 10
Bacteria and Viruses: Microbiology Part I

3. Classification Kingdom Phylum Class Order Family Genus Species
The scientific name includes the genus and species of that organism
Genus is capitalized, species is lowercase
Both are underlined or italicized
Ex. Canis familiaris

4. Bacteria
All the organisms found in the Kingdoms Archaebacteria and Eubacteria
Importance
Pathogenic
Decomposers
Make antibiotics
Help in production of food
Yogurt, cheese, pickles…

5. Kingdom Archaebacteria
Organisms that live in extreme environments
Extreme Thermophiles
Live in very hot or cold environments (hot springs)
Extreme Halophiles
Live in very salty environments (dead sea)
Methanogens
Live in anaerobic environments such as swamps, sewage, intestines
Produce methane gas

6. Kingdom Eubacteria Larger of the two kingdoms
Bacteria we typically think of
Live in many different conditions and are often classified by shape or by their “Gram’s stain”
Shape
Coccus
Bacillus
Spirillum

8. Bacteria Structure of bacterial cells
Cell membrane is phospholipid bilayer
Most have cell wall that contains peptidoglycan
Gram’s stain shows the amount of peptidoglycan in the cell wall
Slimy capsule surrounds the cell
All are prokaryotic cells
No membrane around the nucleus (“cytoplasmic structure”)
Single chromosome appears in the nucleoid region
Flagella

9. Bacteria Reproduction
Bacteria reproduce by binary fission
A type of asexual reproduction
Reproduce at an average of every 30 minutes
Optimal conditions:
Moisture
Temperature
Food
Volume-surface area ratio

10. Structure of Viruses 2 main parts Some have a sheath like envelope
Core: Either DNA or RNA (not both)
Capsid: Protein covering
Some have a sheath like envelope
All viruses are dead without a host
Use organelles and enzymes from the host organism

11. Viruses Virulence Lytic Cycle Ability of a pathogen to affect a cell
Attachment
Entry
Replication and transcription
Assembly
Release

12. Viruses Lysogenic Cycle Latent cell (inactive)
Virus incorporates its genome into the genome of the host organism’s cells
Host cell replicates itself AND virus
Stimulus causes virus to become virulent

13. Viruses Other types of viruses Persistent Infections
Host cell slowly releases virus particles
Does not destroy cell
Transforming Viruses
Add new genetic information
Changes function of cell – no longer productive (warts)

14. Viral diseases
Most often only affect 1 type of organism, and even 1 type of cell within the organism
Rabies and polio attack nervous system
Smallpox and chicken pox attack skin cells
Some viruses release toxins into the blood that can affect other parts of the body
Influenza virus affects respiratory system, but we sometimes get headaches, muscle soreness, nausea…

15. Viral Diseases Controlling Viral Diseases Vaccination programs
Purpose: activate immune system to recognize and respond to virus or other organism and prevent disease
Vaccination types:
Inactivated: virus is altered so it cannot replicate in host cell
Attenuated: “live” virus, but is not virulent

16. Viral Diseases Antiviral Drugs
Interferons: chemicals released by infected cells to inhibit viral replication
Used today, but our knowledge and their effectiveness is still limited

17. Diseases and Disorders
Infectious Diseases
Ailments that are caused by viruses or organisms
Pathogens
The agent that invades the body and causes the disease
Ex. bacteria, viruses, worms…
How they cause disease
Tissue destruction
Toxin formation

18. Diseases and Disorders
Contagious (communicable disease)
A disease that can spread from one person to another

19. How Diseases Spread Airborne infections Direct contact infections
Transmitted by pathogens suspended in water droplets in the air
Direct contact infections
Transmitted by direct contact with sore on skin or mucous membrane of infected person
Indirect contact infections
Touching an object after someone who is infected

20. How Diseases Spread Contamination infections Wound infections
Pathogens enter body by contaminated food or water
Wound infections
Pathogens that enter body through wounds
Vector-carried infections
Transmitted by insects
Immune carriers
Transmitted by individuals immune to disease

21. Body Defenses Structural defenses Skin Mucous membranes Tears
Effective at keeping pathogens out of the body
Mucous membranes
Nasal passages, trachea, lungs
Tears
Protect eye by keeping it moist
Contains Lysozyme – attacks bacterial cell walls

22. Body Defenses Nonspecific Defenses Inflammation Lymphatic system Fever
Chemicals released from cells cause blood vessels to dilate, causing the area to swell
Histamine: chemical released by cells
Lymphatic system
Filters pathogens and toxins from blood
Fever
Increased temperature to kill microorganisms

23. Body Defenses Specific Defenses Antibodies Special cells
Chemicals that circulate in the blood to fight specific pathogens
Special cells
Such as leukocytes, phagocytes

24. Fighting Disease Antibiotics How they work
Chemicals to combat infectious bacterial diseases
Can now be made synthetically
How they work
Inhibit growth of bacteria/pathogen
Destroys bacteria/pathogen