1. Viruses

2. VIRUS
Virologist
A person that
studies viruses!!

3.
Electron Microscope

4. Characteristics Noncellular Contains a protein coat called the capsid
Have a nucleic acid core containing DNA or RNA
Capable of reproducing only when inside a HOST cell

5. What are Viruses?
Core of DNA OR RNA surrounded by a capsid (protein coat)

6. Are they living or nonliving?
LIVING NONLIVING
Does not reproduce
Alone, Needs a HOST in order to survive
Does not grow
Are not made of cells
Contain DNA/RNA
DNA Replicates
Made of lipids, proteins, nucleic acids
Undergo mutations

7. Viral Structure

8. Bacteriophage
VIRUS

9. What are the parts of the virus?
Head
Capsid
DNA/RNA
Tail
Tail fibers

10. Viral Replication (Lytic and Lysogenic Cycles)

11. What are the life cycles of the virus?
Lysogenic
Lytic

12. A Virus attaches to the host and injects its DNA into the cell.
Lytic
A Virus attaches to the host and injects its DNA into the cell.
B The DNA replicates in the host cell.
C The parts of the virus are created.
D The new viruses erupt from the host cell (cell lyses (burst))

13. Lysogenic
A Virus attaches to the host and injects its DNA into the cell.
B The viral DNA attaches to the host DNA.
C DNA replication takes place (Interphase)
D The cell undergoes mitosis
E Stress causes the viral DNA to create the “weird” protein thus creating an outbreak!

14. Lytic vs. Lysogenic
Mysterious Invaders - A Closer Look at Viruses

15. Types of Viruses
Bacterial
Plant
Animal

16. Bacterial Virus
Viruses that attack bacteria are called bacteriophage or just phage

17. Plant Virus
Tobacco Mosaic Virus

18. Animal Viruses

19. Herpes Virus
SIMPLEX I and II

20. Adenovirus
COMMON COLD

21. Influenza Virus

22. Chickenpox Virus

23. Papillomavirus – Warts!

24. Retroviruses

25. Characteristics of Retroviruses
Contain RNA, not DNA
Contain enzyme called Reverse Transcriptase
When a retrovirus infects a cell, it injects its RNA and reverse transcriptase enzyme into the cytoplasm of that cell

26. Retroviruses
The enzyme reverse transcriptase (or RTase), which causes synthesis of a complementary DNA molecule using virus RNA as a template

27. Retroviruses HIV, the AIDS virus, is a retrovirus
Feline Leukemia Virus is also a retrovirus

28. What is a vaccine?
It is a weakened virus or the virus without its RNA/DNA.
It causes the body to react and defend.