1. Virus and Bacteria Outline
A. microscopic,disease
B. Non-living because
C. Host cell
D. Structure (3 parts)
E. Lytic vs. lysogenic
F. Examples
G. vaccine
Bacteria
A. Archae vs. Eu
B. Structure
C. Reproduction
binary fission vs. Conjugation
D. Bad, examples
E. Good, antibiotic

2. Viruses and Bacteria Notes:
Chapter 18

3. Viruses: Microscopic particles that invade cells and cause disease
Non-living because they do not grow or develop or carry out respiration; they can only reproduce inside living cells (called a host cell)

4. Structure of a virus: draw and label
Nucleic acid core: either DNA or RNA
Capsid: outer protein coat
Tail fibers: used to attach to host cell

5. Viruses replicate in lytic or lysogenic cycles: (make a copy)
Lytic cycle (active):
Virus attaches to host cell
Injects viral nucleic acid which destroys host’s DNA
New viruses made inside the cell
Host cell pops, releasing virus to infect other cells

6. Lytic Cycle:

7. Lysogenic Cycle:
Viral DNA is joined with the host cell’s DNA (chromosomes) and can be passed on to daughter cells
Virus is present but not active
Explains why some diseases seem to go away only to reappear later and why some diseases don’t show up for many years

8. Lytic and Lysogenic Cycle:

9. Examples of Viruses: HIV
HIV, flu, chicken pox, colds, hepatitis, measles
Can you guess which diseases are caused by lysogenic cycles and lytic cycles?
HIV

10. Vaccinations:
Use weakened form of a virus to create antibodies against the virus

11. 2 minute review with partner
What are the 3 parts of a virus?
2. Describe the difference between the lytic and lysogenic cycles.

12. Bacteria:(formerly Kingdom Monera)
Archaebacteria:
Prokaryotes
Hetero/autotrophic
Live in extreme environments
Have DNA sequences similar to eukaryotes and are thought to be their ancestors
Eubacteria:
Prokaryotes
Hetero/autotrophic
Live everywhere

13. Structure of a Bacterial Cell:
Strong cell wall; prevents bursting
DNA in single circular chromosome (no nucleus)
Plasmid: small ring of DNA
DNA

14. Shapes of Bacteria: add to notes
Cocci: round shaped
Bacilli: rod shaped
Spirilla: spiral shaped

15. Bacteria replicate (reproduce) by:
Binary Fission: Bacteria reproduce by dividing in half (asexual)
Conjugation: hollow bridge forms b/t cells and genes exchanged (sexual-
called “promiscuity”)

16. The importance of bacteria: (bad)
Cause disease (pathogens)
Ex: strep throat, tetanus, Lyme disease, tooth decay, salmonella, tuberculosis
Fewer deaths from bacterial infections because of sanitation and hygiene (sterilization/pasteuri-zation by heat, disinfectants)
Lyme disease

17. The importance of bacteria: (good)
Recycle nutrients through decomposition
Nitrogen fixation: convert nitrogen into a form plants can use
Foods: cheese, yogurt
Medicines: produce antibiotics to kill bacteria by blocking growth /reproduction; insulin

18. 2 minute review with a partner
How do bacteria reproduce?
Each give one good thing about bacteria.
Each give something bad caused by bacteria.