1. Bacteria, viruses and the immune system
Biology

2. 2 Bacteria Kingdoms Archaebacteria Eubacteria Harsh environment
High temperatures
High salinity
Acidic
Eubacteria
Found in normal environments.
These are the type of bacteria that we come into contact with on a daily basis!!!

3. General Structure of Bacteria
 Prokaryotic
No nucleus or membrane bound organelles
Lots of ribosomes
Thick cell wall
Circular chromosomes (DNA)
Some have a sticky capsid located outside the cell wall; this allows them to stick to surfaces…. like your teeth!! 

4. General Structure of a Bacterial Cell

5. Bacterial Reproduction
Reproduce by binary fission
Asexual reproduction
Makes an exact copy
Happens quickly

6. Binary Fission in Bacterial Cells
Bacteria Grows
DNA replication occurs
Cytokinesis occurs
Two identical cells result

7. Bacteria…Good, Bad or Both?
Bacteria is good!
food (yogurt)
medicines (insulin)
recycles nutrients
decompose
nitrogen fixation (in plants)
Bacteria is bad!
Decay/rot food
Rot teeth
Cause disease/
infections
(strep throat)

8. Antibiotics Antibiotics are used to clear up bacterial infections.
Antibiotics put holes into bacterial cell walls causing them to burst and die.

9. Viruses
Considered to be nonliving because it cannot reproduce on its own
General Structure
Protein coat on the outside
Nucleic acid on the inside (DNA or RNA)

10. Virus Structure

11. Examples of Viruses Influenza- the flu HIV- AIDS
Varicella- chicken pox & shingles
Polio virus- polio
Rubella or measles- measles
Rhinovirus- cold

12. Reproductive Cycles Lytic Cycle Virus DNA enters the host cell
Hijacks host to make DNA and protein
Host cell puts viruses together
Cell bursts and releases virus

13. Lysogenic Cycle Lysogenic Cycle Very similar to lytic cycle
Virus DNA is integrated into host cell
Cell eventually ruptures with new virus after several generations

14. Examples of Viruses with a Lysogenic Cycle
HIV
Herpes Simplex I = Cold sores
Herpes Simplex II = Genital herpes
Varicella = Chicken pox/ Shingles

16. Our Immune System
Responsible for protecting the body from diseases caused by bacteria and viruses

17. Lines of Defense 1st line: skin and mucus
Skin acts as a barrier
Mucus traps microorganisms
2nd line: cells release chemicals
blood flow to invaded region increases (swelling)
Raises body temperature (fever)

18. 3rd line: Special white blood cells attack invaders
foreign antigens are detected and Helper T white blood cells are alerted
Helper T cells “activate” white blood cells called B cells
B cells multiply and either become plasma cells or Memory B cells
Plasma cells produce antibodies that attach to the foreign antigens and “mark” them for destruction
Memory B cells stay in the body in case another infection arises

20. Uh OH!!! What if a cell is already infected?!?!?!
Helper T cells alert Killer T cells
Killer T cells poke holes in the infected cell to kill it

21. Types of Immunity Active Immunity Exposed to disease
Develop disease and become immune
Longer lasting
Passive Immunity
Injected with antibody that another organism made
Not permanent
Some vaccines have to be received every year because the pathogen that causes the illness is always mutating!!!