Infectious Diseases Unit 4 Lesson 4 plan

Do now What are the two ways a pathogen causes damage?

Do now What are the two ways a pathogen causes damage? – Direct – Indirect

Do now What are the two ways a pathogen causes damage? – Direct – Indirect What feature do both types of damage have in common?

Do now What are the two ways a pathogen causes damage? – Direct – Indirect What feature do both types of damage have in common? They cause host cell lysis

Do now Can you remember how bacterial pathogens make you sick? Today, we’ll consider how a virus damages a host (i.e. how it makes us sick!). Let’s pretend a virus in our body is a lone soldier in enemy territory and one of our cells is a factory the soldier encounters. How could the soldier use the factory if he was carrying building information?

Discussion How viruses make us sick.

How do viruses make us sick? Viruses damage through their main goal: Making more viruses! Do you remember the two ways bacteria cause damage?

But viruses need our cells to reproduce. The viral lifecycle has three stages: 1. Enter the cell 2. Replicate 3. Exit the cell

Remember a virus needs to use a cell and evolution has molded this ability: 1.First the virus attaches to the cell it is going to infect. 2.Then the virus enters the cell. Surface receptors of HINI

Replication strategies depend on the genetic code the virus has. RNA viruses DNA viruses

Before we can learn how viruses replicate we need to remember molecular dogma! DNARNAProtein

Before we can learn how viruses replicate we need to remember molecular dogma! DNARNAProtein TranscriptionTranslationReplication Where in the cell do these processes take place?

Before we can learn how viruses replicate we need to remember molecular dogma!

DNA viruses follow molecular dogma They need to get their DNA into the nucleus Herpesvirus is a DNA virus DNA DNA  RNA  PROTEIN

host proteins DNA Viruses need host proteins to replicate Herpesvirus is a DNA virus DNA DNA  RNA  PROTEIN

RNA  RNA  PROTEIN RNA viruses bring this enzyme with them 1.RNA viruses defy molecular dogma by making RNA from RNA 2.To do this they bring specialized enzymes with them H1N1

DNA RNA  DNA  RNA  PROTEIN 1.Retroviruses like HIV are RNA viruses 2. They defy molecular dogma! 3.They make DNA from RNA

DNA RNA  DNA  RNA  PROTEIN Retroviruses bring the reverse transcriptase enzyme with them. They use an integrase, to insert the DNA into the host genome. 1.Retroviruses defy molecular dogma by making DNA from RNA 2.To do this they bring specialized enzymes with them

RNA viruses cannot correct errors Random uncorrected mutations in RNA viruses cause Antigenic Drift

Exit strategies Can you remember the exit strategies for: Naked viruses? Enveloped viruses?

Wrap up How do virus make you sick? Which strategy for survival is best for viruses? What is the most convincing evidence for your answer?