1. Bacteria

2. I. Prokaryotes
Prokaryotes: single-celled organisms that lack a nucleus
1. Eubacteria – common bacteria
2. Archaebacteria – lives in extreme harsh environments

3. Identifying Prokaryotes
1. Shapes
a. Bacilli (rod shaped)
b. Cocci (spherical/circle)
c. Spirilla (spiral)

4. a. Gram-positive (w/peptidoglycan) – purple
Gram Staining: Helps to determine what type of antibiotic to use
To treat the bacterial infection
2. Cell Walls
a. Gram-positive (w/peptidoglycan) – purple
b. Gram-negative (w/o peptidoglycan – red
Peptidoglycan is a sugar

5. Staphyl: Clumps or clusters b. Strepto: long chains c. Diplo: pairs
3. Arrangement
Staphyl: Clumps or clusters
b. Strepto: long chains
c. Diplo: pairs

6. 4. Movement Propelled by tail-like structure called flagella
b. Glide along a slime secretion
c. Move along like snakes
d. Some don’t move

7. Obtaining Energy
1. Autotrophs
a. Photoautotrophs: obtain energy from photosynthesis
b. Chemoautotrophs: obtain energy from inorganic molecules

8. 2. Heterotrophs
a. Can cause food poisoning
b. Photoheterotrophs: photosynthetic, but also need organic compounds for nutrition

9. Releasing Energy
1. Obligate aerobes: require oxygen
2. Obligate anaerobes: cannot live in presence of oxygen
3. Faciltative anaerobes: do not need oxygen, but can live in the presence of it

10. Growth and Reproduction
1. Binary fission: cell divides, asexual
2. Conjugation: transfer of genetic information from one cell to another, sexual
3. In unfavorable conditions, many bacteria can form endospores – can remain dormant for months or years

11. II. Bacteria in Nature Decomposers
1. Help recycle nutrients – break down dead organisms
2. Used in sewage treatment

12. Nitrogen Fixers
1. Nitrogen fixation: converting nitrogen into a form plants can use
(EX: Rhizobium grow on roots of soybeans and other legumes – converts nitrogen to ammonia for the plant)

13. Bacteria and Disease
1. Pathogen: disease-causing agents
2. 2 ways bacteria cause disease
a. Break down tissues for food
b. Release toxins
3. Many can be treated with antibiotics

14. Human Uses of Bacteria
1. Food – cheese, yogurt, buttermilk, sour cream, pickles, sauerkraut
2. Industry – cleaning up oil spills, mining minerals, synthesizing drugs

15. 3. Bacteria live in our digestive tract to help in digestion (called normal flora)

16. Controlling Bacteria
1. Sterilization: destroy bacteria by subjecting them to great heat or chemicals
a. Boiling, frying, steaming can all kill bacteria
b. Disinfectant chemical solutions can be used in homes and hospitals
2. Refrigeration – bacteria grow slowly at low temperatures

17. Antibiotics
Fighting Bacteria Bacterial disease can be fought with soap, chemicals, and antibiotics.
Antibiotic-Resistant Bacteria Mutations that confer resistance to antibiotics are strongly favored in bacterial populations being treated with an antibiotic. 14

18. Viruses

19. A virus is an infectious agent made up of nucleic acid (DNA or RNA) wrapped in a protein coat called a capsid.
Viruses have no nucleus, no organelles, no cytoplasm or cell membrane—Non-cellular
This is why it does NOT belong to any kingdom. vs

20. Virus Parts

21. Viruses with RNA that transcribe into DNA are called retroviruses.
Viruses are parasites—an organism that depends entirely upon another living organism (a host) for its existence in such a way that it harms that organism.
HIV Infected Cell
(This is the reason why HIV is so incurable.)
A flea is a parasite to a dog and is harmful to the dog.

22. Certain viruses can only attack certain cell types
Certain viruses can only attack certain cell types. They are said to be specific.
Example: The rabies virus only attacks brain or nervous cells.
Surface Markers
Virus
Receptor Sites
It’s like the pieces of a puzzle. The ends have to match up so only certain pieces fit.
Cell

23. A virus recognizes cells it can infect by matching its surface marker with a receptor site on a cell.
Virus
Surface Markers
Cell
Receptor Sites

24. Viral Infection
1. Infect cells and replicates inside host cell
2. Bacteriophage: viruses that infect bacteria

25. 3. 2 types of viral infections
a. Lytic infection: virus enters cell, make copies of itself and causes the cell to burst
b. Lysogenic infection: virus embeds its DNA into the DNA of host and is replicated with host cell’s DNA

26. Lytic Cycle

27. Lysogenic Cycle

28. Viruses and Disease
1. Many viruses can be prevented through the use of vaccines (polio,
measles, influenza)
Vaccines are parts of a virus that are injected into you so that your body can recognize the parts and build antibodies to fight against the virus – not a cure
2. Oncogenic viruses cause cancer
3. Prions contain no DNA or RNA, only protein

29. Importance: Beneficial: *Harmful Causes disease—pathogenic
Disease producing agent—pathogen
Human Diseases: Warts, common cold, Influenza (flu), Smallpox, Ebola, Herpes, AIDS, Chicken pox, Rabies
Viruses disrupt the body’s normal equilibrium/balance
Viruses can be prevented with vaccines, but NOT treated with antibiotics.
(antibiotics treat bacteria)
Beneficial:
Genetic Engineering—harmless virus carries good genes into cells.

30. Virus
Living Cell
Cell membrane, cytoplasm, genetic material, organelles
RNA or DNA core (center), protein coat (capsid)
Structure
Copies itself only inside host cell--REPLICATION
Asexual or Sexual
Reproduction
DNA and RNA
Genetic Material
DNA or RNA
Growth and Development NO
YES—Multicellular Organisms
Obtain and Use Energy NO
YES
Response to Environment
YES NO
Change over time NO
YES