Infectious DiseasesUnit 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

• How do you think a virus causes damage to the host?

Discussion

• How viruses make us sick.

The viral lifecycle has three stages:

The virus needs to enter the cell

The virus needs to replicate

The virus needs to exit the cell

How viruses make us sick

Key goal

Make more virus!

Remember a virus needs to enter the cell:

1. First the virus attaches to the cell it is going to infect.

2. Then the virus enters the cell.

Surface receptors of HINI

Viral replication

• RNA viruses

• DNA viruses

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

DNA RNA Protein

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

DNA RNA Protein

Transcription TranslationReplication

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 RNA PROTEIN

DNA Viruses need host proteins to replicate

Herpesvirus is a DNA virus

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

RNA DNA RNA PROTEIN

1. Retroviruses like HIV are RNA viruses2. They defy molecular dogma! 3. They make DNA from RNA

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

• Recap!