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Why Do We Need To Why Do We Need To Understand the Structure of Understand the Structure of

Viruses and How they Viruses and How they Replicate?Replicate?

http://www.youtube.com/watch?v=kiG-c964ejQ&NR=1

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Things to Think about Things to Think about

How can understanding HIV replication How can understanding HIV replication help prevent or stop the progress of help prevent or stop the progress of the virus into developing AIDS?the virus into developing AIDS?

Are you thinking about getting an HPV Are you thinking about getting an HPV vaccine? What exactly is it?vaccine? What exactly is it?

How can viruses be used to treat How can viruses be used to treat cancer?cancer?

VIRUSES ARE THEY CONSIDERED LIVING?VIRUSES ARE THEY CONSIDERED LIVING? Not considered living because:Not considered living because:

How do they get their energy? They are How do they get their energy? They are parasitesparasites

So, what is a virus?So, what is a virus?

Characteristics of VirusesCharacteristics of Viruses

Strains of viruses are designed to Strains of viruses are designed to attack specific host organismsattack specific host organisms– Tobacco virus Tobacco virus → tobacco plant→ tobacco plant– Bacteriophage → bacteriumBacteriophage → bacterium

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DNA vs. RNA

DNA vs. RNA DNA – “blueprint” - codes for all the

proteins that the body requires to function

Structure of BacteriophageStructure of Bacteriophage

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REPRODUCTION OF VIRUSES:REPRODUCTION OF VIRUSES:LYTIC CYCLELYTIC CYCLE

Step 1

End Result

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LYSOGENIC CYCLELYSOGENIC CYCLE

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BOTH CYCLESBOTH CYCLES

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QuestionsQuestions

What are the advantages/disadvantages of What are the advantages/disadvantages of each cycle?each cycle?

Do the host cells have any defense Do the host cells have any defense mechanisms?mechanisms?

________________________________________________________________________________________________________________________________________________________________________________

How can we manipulate this process for How can we manipulate this process for our own purposes?our own purposes?

RNA VirusRNA Virus

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RetrovirusRetrovirus Genetic material = _____________Genetic material = _____________ Instruct host cell to use viral _________ to Instruct host cell to use viral _________ to

create viral _________create viral _________

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HUMAN IMMUNODEFICIENCY HUMAN IMMUNODEFICIENCY VIRUSVIRUS

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REPLICATION IN T CELLSREPLICATION IN T CELLS

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A.I.D.S.A.I.D.S. Affects immune system by weakening itAffects immune system by weakening it

T cells B cells antibodiesT cells B cells antibodies

Die from ______________________Die from ______________________

HIV is an international problem = HIV is an international problem = pandemicpandemic

Preventive measures can stop spreadPreventive measures can stop spread

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Most of the time it is a silent killerMost of the time it is a silent killer

Responsible for _____________________Responsible for _____________________

Can be prevented in caught in time!Can be prevented in caught in time!

Prevention: ________________________Prevention: ________________________

If you are sexually active get a PAP test!!!If you are sexually active get a PAP test!!!

PAP detects abnormal cells which lead to PAP detects abnormal cells which lead to cancercancer

IMMUNE RESPONSE

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VaccinesVaccines1.1. ACTIVE IMMUNITY: Stimulate the body to ACTIVE IMMUNITY: Stimulate the body to

produce antibodies against the diseaseproduce antibodies against the disease

2. PASSIVE IMMUNITY: antibodies are given from one 2. PASSIVE IMMUNITY: antibodies are given from one individual to the other individual, usually individual to the other individual, usually temporarytemporary

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Manipulating VirusesManipulating Viruses

E.g. herpes virus can be manipulated E.g. herpes virus can be manipulated to only infect cancer cellsto only infect cancer cells

Nanotechnology or bioengineering: Nanotechnology or bioengineering: using viruses to deliver drugsusing viruses to deliver drugs

Follow-up with HWFollow-up with HW

Textbook Page # 30 Textbook Page # 30

Question # 1-4Question # 1-4

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