Virus Structure, Classification, and Cycles of Infection

1. Virus Structure, Classification, and Cycles of Infection Sam Linso, Ted Schoenharl, Ethan Fleming

2. Overview

3. SL What is a Virus? • Virus-Non-living particle made of proteins, nucleic acids, and sometimes lipids • Only reproduce by infecting living cells • Vary in size and shape • All bacteria has protein coat called a capsid • May also have additional membrane

4. SL Structures and Differences • Use genetic information to replicate themselves • Trick infected cells with proteins on surface • Animal virus affects animal, plant virus affects plant

5. SL What Traits do Viruses Share? • Viruses are neither living or non-living • All viruses have capsid proteins • All have DNA or RNA

6. Similarities and Differences

7. EF What do Viruses Need to Create New Viruses? • Can only use living cells to reproduce • Takes advantage of the nutrients and cellular machinery • Harms host cells in the process

8. EF What Type of Cells can Viruses Infect? • Can only infect living cells • Plant viruses infect certain Plant cells • Animal viruses infect only certain animal cells • Bacterial viruses can only infect certain bacterial cells

9. EF Define Bacteriophages • Word means bacteria eaters • Infect bacteria then reproduce

10. EF Diseases Caused by RNA Viruses: Common Cold and HIV • Retrovirus- Genetic info is copied from RNA to DNA not DNA to RNA • HIV:  • Virus makes DNA copy of RNA and inserts it into host cell's DNA • The virus DNA will destroy immune system • The Common Cold: • Attacks where protein makes RNA • Host cell mistakes virus and makes more copies 

11. TS Lytic Cycle • Step 1: Virus injects DNA into bacterium • Step 2:Viral genes transcribed  by host cells(Bacterial DNA) • Step 3:Virus makes new viral DNA • Step 4:Protiens/ Nucleic acids build new viruses • Step 5:Viralenzymeslysethe bacterium wall, spread and infect bacteria cells

12. TS Define Prophage • Bacteriophage DNA that becomes embedded in the bacteria's host DNA

13. TS Lysogenic Cycle  • Step 1: Virus injects DNAinto bacterium • Step 2:Viral DNA inserts itself into a BacterialChromosome • Step 3: Prophage Replicates with the bacterium • Step 4: The prophage exits thebacterial chromosome and enters the lytic cycle

14. TS Lysogenic vs Lytic  Lysogenic Lytic No Prophage Host Cell is Bacterial DNA Both • Virus Injects DNA into Bacterium  • Viral Enzymes Both lyse the cells walls • Prophage • Host Cell is Viral DNA

15. SL What is the Coating on a Virus Called? A    Phage B    Capsid C    Pathogen D    L-Cell Coating

16. SL In What Way are Viruses and Cells Similar? A    Viruses only use RNA B     They both respond to the environment C      Both obtain and use energy D    They both change over time

17. EF  What Kind of Cell Can All Viruses Infect?  A     Plant Cells B      Bacteria Cells C      Living Cells D      Dead Cells

18. EF What Type of Cell Do Bacteriophages Infect A     Plant Cells B     Dead Cells C     Animal Cells D    Bacteria Cells

19. What is the first step of both the processes? Viral enzymes lyse the bacterium wall, spread and infect bacteria cells A. B. Virus makes new viral DNA C. Virus injects DNA into bacterium D. Proteins/ Nucleic acids build new viruses

20. What happens when viral enzymes lyse the bacteria wall? A. Virus makes new viral DNA B. Viral DNA inserts itself into Bacterial Chromosome C. spread and infect bacteria cells D. Prophage Replicates with the bacterium

21. Overview