Medicines and Drugs

Anti-viralsJulia Barnes

Anna Cruickshank

Objectives D.7.1 State how viruses differ from

bacteria. D.7.2 Describe the different ways in which

antiviral drugs work. D.7.3 Discuss the difficulties associated

with solving the AIDS problem.

Virus vs. Bacteria

Acellular Not living Don’t metabolize energy or

produce ATP Cannot reproduce

independently Usually surrounded by a

protein capsid as well as a cell membrane

No nucleus or cytoplasm Have DNA or RNA 100 nm (nanometers)

Cellular Living Do metabolize energy and produce ATP Do reproduce independently Maintain a cell membrane but not a protein capsid Nucleus and cytoplasm Have DNA or RNA 1000 nm

Virus vs. BacteriaStructure

Click on Picture

Antiviral Drugs How the virus works

Invades host cell Using enzymatic processes the virus stimulates the host

cell to produce viral nucleic acid Viral nucleic acid is coated with protein and released from

host cell

How antivirals work Chemically block enzyme activity in host cell

This stops the virus from replicating Altering the host cell’s ribosomes, making them useless to

the virus

More Specifically…

Possiblities for Intervention Alteration of host binding site Alteration of cell wall Prevention of virus losing its

protein coat Blocking reverse

transcriptase HIV and AZT

Altering genetics of virus Prevention of virus exit from

cell Influenza and amantadine

YA! MOVIE!

http://www.csb.yale.edu/userguides/graphics/ribbons/help/dna_rgb.gif

http://www.youtube.com/watch?v=RO8MP3wMvqg&feature=related&safety_mode=true&persist_safety_mode=1

AIDSAcquired Immune Deficiency Syndrome

HIV Retrovirus (RNA instead of DNA) Attacks white blood cells – disables immune

system Uses reverse transcriptase to make DNA copies

off of the virus’ RNA

HIV Invasion Process

Click on Picture

Possible AIDS Drugs Chemical group -

nucleoside analog reverse transcriptase inhibitors

AZT (3'-azido-3'-deoxythymidine) sold under Retrovir or Retrovis

Inhibits reverse transcriptase enzyme

Does not inhibit normal cell activity

Difficulties With TreatmentGenerally Speedy reproduction

Fast evolution and mutation

Thousands of reproduced viruses by the appearance of symptoms

Difficult to entirely eliminate viruses Oral herpes treated with

acyclovir

For 5 Points… What is one difference between bacteria

and a virus?

Acellular Not living Don’t metabolize energy or produce

ATP Cannot reproduce independently Usually surrounded by a protein capsid

as well as a cell membrane No nucleus or cytoplasm Have DNA or RNA smaller

Cellular Living Do metabolize energy and produce

ATP Do reproduce independently Maintain a cell membrane but not a

protein capsid Nucleus and cytoplasm Have DNA or RNA larger

For 10 Points… What must a virus have before it can

replicate or reproduce?

A host cell

For 15 Points… What are TWO ways antivirals alter the

host cell?

Blocking enzyme activity or altering the ribosomes

For 20 Points… What is the name of the capsule containing

the viral RNA?

The Capsid

For 25 Points… Name a possible AIDS medicine and what it

does in the cell.

AZT blocks reverse transcriptase enzyme