1. VIRUS MEANS “POISON”!

2. MADE OF PROTEIN AND NUCLEIC ACID (EITHER DNA or RNA)

3. Protein part is the CAPSID NA is insidecapsid

4. Living or Not? They have genetic material & structural proteins

5. BUT: No Ribosomes No Organelles No Nucleus Can’t Use Energy

6. AND: They Cannot Reproduce on their own

7. SO: They are NON-LIVING!

8. referred to as ObligateIntracellularParasites

9. They need a HOST CELL in order to replicate.

10. They can be classified 3 Ways:

11. INTERESTINGSHAPES! Polyhedron,Helical,Complex

12. Some are “enveloped” with a membrane- like structure

13. Their nucleic acid type: Either DNA or RNA virus

14. DNA virus:DNA is inserted into cell, then protein synthesis using virus mRNA

15. OR, Virus DNA joins host cell DNA and replicates with host cell DNA

16. RNA Virus: virus RNA is inserted into host cell,makes proteins directly

17. OR, RNA retrovirus: DNA, made by reverse transcription, joins host DNA, followed by protein synthesis

18. Classified by whether or not the virus is disease-causing

19. Virus can be “virulent”--causes disease right away (like a cold or flu)

20. If virulent, they undergo the LYTIC CYCLE

21. Lytic Cycle: 1) Adsorption: virus attaches to host cell

22. 2) Entry: virus NA is injected into host cell

23. 3) Replication: Host cell starts making virus parts

24. 4) Assembly: virus parts get put together

25. 5) Release: host cell gets so full of new viruses that it bursts, releasing viruses

26. Virus can be “temperate”--waits to cause disease later (like HIV)

27. a) If temperate, virus goes into the LYSOGENIC CYCLE

28. b) LYSOGENIC CYCLE: Starts like lytic cycle with adsorption & entry

29. c) Then, Attachment: virus DNA joins with host DNA

30. d) Replication: Host cell undergoes replication; virus DNA gets copied

31. e) Activation: something triggers the virus to become virulent (lytic)

32. Then,it starts the LYTIC CYCLE and causes infection (disease).

33. How are viruses spread? Bodily fluids Through air, water Direct contact

34. What is smaller than a virus? Viroid--NA only cause plant diseases

35. Prion--small strand of amino acids; mammal diseases like CWD or Mad Cow disease

36. How could you prevent viral infections? Vaccinations Wash hands! Cover your mouth when sneezing or coughing! sneezing or coughing! Safe sex!