1. VIRUSES AND BACTERIA

2.  Composed of a nucleic acid with a protein coat ◦ What’s a nucleic acid??? ◦ Protein coat is called a capsid  NOT ALIVE ◦ Not made of cells ◦ Don’t grow ◦ Don’t reproduce by themselves ◦ Don’t use energy ◦ Can be dormant for hundreds of years

3.  Nucleic acid has instructions for making more virus ◦ Range in size ◦ Some have 4 genes, some have hundreds  Protein arrangement determines the shape

5.  What are the 2 parts of a virus?  What are the two nucleic acids?  Give one reason why viruses are not ALIVE (there are 4)  What is a capsid?  Why can’t you “kill” a virus?

6.  Replicate using a host cell  What does replicate mean?  Bacteriophage = virus that infects a bacteria ◦ they can infect bacteria IN YOUR BODY!!!  Some viruses are specific and infect only certain cells or species ◦ Example: tobacco mosaic virus ◦ Others infect a variety of cells and species  Example: influenza

7.  Replication ◦ Viral DNA or RNA takes over cell’s metabolism ◦ Viral genome hijacks cell into making parts for itself ◦ Cell fills up with viruses and bursts open

9.  Flu Attack video Flu Attack video

10.  How do viruses replicate?  What is a bacteriophage?

11.  Retroviruses ◦ RNA-containing virus gets into cells ◦ Virus uses reverse-transcriptase (an enzyme) to reverse-engineer DNA from its RNA ◦ DNA is integrated into host cell’s chromosome  Presence of reverse-transcriptase in a person is evidence that they have a retrovirus  Common retrovirus: HIV

12.  If not alive—where did they come from? ◦ Ancestral form of life?  NO—they can’t reproduce w/o host cell ◦ Originated from host cell?  maybe  Piece of nucleic acid that broke free  Stayed inside cell with ability to reproduce parasitically ◦ From outer space??

13.  Name one common retrovirus  What enzyme makes viral DNA using its RNA?

14.  ARE ALIVE – microorganisms ◦ Made of cells ◦ Reproduce by themselves ◦ Grow and use energy  Single-celled  Not all are harmful! Most are good! ◦ Cheese, yogurt, beer… ◦ E. coli in your intestines ◦ Etc.

15.  No nucleus or organelles (prokaryotic)  Consist of one cell surrounded by a cell wall ◦ Wall is different from that found in plant cells  May also have a capsule surrounding cell wall ◦ Bacteria with a capsule are more likely to cause disease

16.  Often have flagella or cilia for movement

17. ◦ Some secrete toxins as part of their metabolism  Examples of pathogenic bacteria: ◦ Strep throat ◦ Tetanus ◦ Pneumonia

18.  Prevention and treatment of infections ◦ Antibiotics: attack and kill bacteria  Antibiotic-resistant bacteria ◦ Antitoxin  Botulism ◦ Sterilization: cleaning wound/implements ◦ Vaccination: injecting heat-killed bacteria so person will make antibodies

19.  What is significant about a bacterium with a capsule?  Give one method of killing or preventing bacterial infections (there are 4)

20.  How do you treat/prevent viruses? ◦ Vaccination – prevents ◦ To “kill”:  Bleach  Ultraviolet light  Heat  That’s it…no medicines…  Viruses are ALL PATHOGENIC

21.  What is the only way to prevent viral infections?  Give one method of “killing” viruses (there are 3)  Give one way bacteria and viruses are different

22.  Scale of the Universe Scale of the Universe

23.  Top 5 Deadliest Diseases Top 5 Deadliest Diseases