Why Do We Need To Understand the Structure of Viruses and How they Replicate? 1 http://www.youtube.com/watch?v=kiG-c964ejQ&NR=1

Things to Think about How can understanding HIV replication help prevent or stop the progress of the virus into developing AIDS? Are you thinking about getting an HPV vaccine? What exactly is it? How can we prevent pandemics? How can viruses be used to treat cancer? 2

VIRUSES ARE THEY CONSIDERED LIVING? Not considered living because: How do they get their energy? They are parasites So, what is a virus?

Characteristics of Viruses Strains of viruses are designed to attack specific host organisms Tobacco virus → tobacco plant Bacteriophage → bacterium Genetic material can be _______or ___________ 4

DNA vs. RNA

DNA vs. RNA DNA – “blueprint” - codes for all the proteins that the body requires to function

Structure of Bacteriophage 7

http://www.bbc.com/news/world-latin-america-36184799

REPRODUCTION OF VIRUSES: LYTIC CYCLE Step 1 End Result 9

LYSOGENIC CYCLE http://www.youtube.com/watch?v=41aqxcxsX2w&feature=related https://www.youtube.com/watch?v=Rpj0emEGShQ how flu attacks 10

BOTH CYCLES 11

Questions What are the advantages/disadvantages of each cycle? Do the host cells have any defense mechanisms? _____________________________________________ ___________________________________________ How can we manipulate this process for our own purposes? 12

RNA Virus Genetic material = ________________ RNA enters host cell and acts like __________. mRNA intsructs host cell to produce its own mRNA and therefore produce viral proteins mRNA provides its own instructions and ______________________________________ ____________________________________ RNA viruses only go through __________cycle 13

Retrovirus Genetic material = _____________ Instruct host cell to use viral _________ to create viral _________ ____________________________________– enzyme used to synthesize new viral DNA from viral RNA template Viral DNA becomes part of host’s genetic makeup and instructs cell to make viral protein Goes through ___________________ cycle 14

HUMAN IMMUNODEFICIENCY VIRUS 15

REPLICATION IN T CELLS 16

A.I.D.S. Affects immune system by weakening it T cells B cells antibodies Die from ______________________ HIV is an international problem = pandemic Preventive measures can stop spread 17

Most of the time it is a silent killer Responsible for _____________________ Can be prevented in caught in time! Prevention: ________________________ If you are sexually active get a PAP test!!! PAP detects abnormal cells which lead to cancer 18

IMMUNE RESPONSE

Vaccines ACTIVE IMMUNITY: Stimulate the body to produce antibodies against the disease 2. PASSIVE IMMUNITY: antibodies are given from one individual to the other individual, usually temporary 22

Follow-up with HW Textbook Page # 30 Question # 1-4 23