1. WHAT IS A VIRUS? A NONLIVING, NONCELLULAR PARTICLE MADE UP OF GENETIC MATERIAL AND PROTEIN

2. STRUCTURE OF A VIRUS CORE OF NUCLEIC ACID CAN BE DNA/RNA SURROUNDED BY A PROTEIN COAT HEAD (CAPSID)

3. BACTERIOPHAGE

4. Viral Structures

5. SIZES OF VIRUSES FROM 10-400 NANOMETERS (1 billionth of a meter) A nanometer is one billionth of a meter E. Coli Bacteria-2000-2500 nm

6. SPECIFICITY VIRUSES INFECT SPECIFIC ORGANISMS PLANT VIRUSES DO NOT INFECT ANIMALS SOME ONLY INFECT HUMANS RABIES INFECT ALL MAMMALS AND SOME BIRDS SOME INFECT CLOSELY RELATED SPECIES

7. <<<< VIRAL REPRODUCTIO N CYCLE <> LIFE CYCLE OF LYTIC VIRUSESLYTIC LYTIC-CAUSES HOST CELL TO LYSE 1. INFECTION-VIRUS ACTIVATED BY CONTACT W/HOST CELL, INJECTS VIRAL GENETIC MATERIAL

8. LIFE CYCLE CONTINUED 2. GROWTH-HOST CELL CAN’T DISTINGUISH HOST VS. VIRAL DNA-VIRAL GENES SHUT OFF HOST GENES 3. REPLICATION-USES HOST CELL MATERIAL TO MAKE COPIES OF PROTEIN COAT & DNA 4. LYSIS –LAST STAGE CELL RELEASES REPLICATED VIRUS

9. LysogenicLysogenic Virus Cycle

10. RETROVIRUSES CONTAIN RNA RETRO-means backwards. RNA TO DNA After infection VIRUS produces DNA COPY from its RNA using the enzyme Revere Transcriptase Viral DNA is INSERTED into HOST cells & new Virus copies are made

11. TRANSMISSION INSECT BITE BITE OF INFECTED ANIMAL CONTAMINATED FOOD, WATER, BLOOD, SEXUAL CONTACT NEEDLES OR AIR

12. SYMPTOMS EVIDENCE OF DISEASE SUCH AS: RASH FEVER PARALYSIS HEADACHE ACHES SWOLLEN GLANDS CONGESTION

13. TREATING VIRUSES VACCINES CAN CONSIST OF LIVE OR (attenuated) altered BACTERIA OR VIRUSES contain ANTIGENS (surface proteins) from the virus. They stimulate the immune system of an organism to make antibodies Vaccines can be given orally, inhaled or injected

14. TREATING VIRUSES Why do vaccines not always work? A Virus can mutate its surface proteins. The organism’s immune system may not detect the changed protein and not attack it. –Example flu virus Each year a new flu vaccine has to be made because of mutated proteins

15. http://resources.schoolscience.co.uk/ABPI/immune/imm Anim3.htm VACCINE ANIMATION Creation of antibodies