Not the Virus!

1. Not the Virus! If it is not alive, We can’t kill it -- We can only wish to contain it!

2. What the heebiegeebies is this?

3. Major Components of ALL Viruses • PROTEIN COAT CALLED A CAPSID • SOME TYPE OF NUCLEIC ACID

4. What is the main difference between bacterial viruses and animal viruses? • How the nucleic acid enters the host cell • INJECTION VS. ENGULFMENT PROK ANIMAL

6. Bacteriophage Virus that infects a bacteria Do not harm humans Tobacco Mosaic Virus First virus discovered in tobacco plants. Does not harm humans. Influenza Common flu Can affect birds and humans Can cause epidemics- Spanish Flu Adenovirus Common flu Respiratory system infection Not serious

7. Figure 19-10 Lytic and Lysogenic Infections Viral reproduction: Lytic Cycle Host range: infection of a limited range of host cells (receptor molecules on the surface of cells) The lytic cycle: 1- attachment 2- injection 3- hydrolyzation 4- assembly 5- release Results in death of host cell Virulent virus (phage reproduction only by the lytic cycle) Viral reproduction: Lysogenic Cycle Genome replicated w/o destroying the host cell Genetic material of virus becomes incorporated into the host cell DNA (prophage DNA) Temperate virus (phages capable of using the lytic and lysogenic cycles) May give rise to lytic cycle

8. DNA virus Cycle

9. HERPES!!!!!!!! Is it in you?! After the initial infection, some experience sporadic episodes or outbreaks. Caused by STI and fluid contact Only transmitted during outbreak or with sores…hard to transfer during latency

12. Reverse transcriptase • Use enzyme reverse transcriptase to transcribe RNA into DNA

14. Retroviruses • Contain reverse transcriptase • Inserts DNA into host cell • Can lay dormant for years • Has been linked to cancer

15. Retrovirus cycle

16. LysogenicLytic

18. Vaccines • Biological preparation that improves immunity • Contains an agent that resembles a virus/disease causing microorganism • Stimulates immune system to recognize and destroy