1. Set up today’s page in your journal…
Date:
Title: Viral Structure
Essential Question: How does the structure of a virus compare to a cell?
YES - Cornell notes, please!

2. Content Objective BIO.4C The student will:
compare the structures of viruses to cells,
describe viral reproduction
describe the role of viruses in causing diseases such as human immunodeficiency virus (HIV) and influenza.

3. Our new unit: Viruses

4. Essential Vocabulary Virus: a non-cellular (or acellular) pathogen
Pathogen: any disease-causing agent
Virology: the study of viruses
Virion: a viral particle (piece of a virus)

5. Viral components Genetic material (core) Capsid Envelope Spikes
DNA or RNA
Surrounded by the capsid
Capsid
“Coat” Made of proteins
Surrounds the DNA/RNA core
Envelope
Made of lipids (like cell membranes!)
ONLY ON SOME VIRUSES
Spikes
Made of glycoproteins
Used to attach to cells
ONLY ON VIRUSES WITH ENVELOPES

6. Viruses can be… Naked viruses Lack (don’t have) envelopes OR…
Enveloped viruses have envelopes
So, based on what we see here. What are some differences we see between viruses and cells?

7. Draw and Label these in your notes!
DNA
RNA
CAPSID
RNA
CAPSID
CAPSID
ENVELOPE
Draw and Label these in your notes!

10. Cellular Organisms vs Acellular Particles
Eukaryotic Cell
A virus’s size helps it to reproduce. We’ll talk about this tomorrow.
Virus
Prokaryotic Cell
If a cell was the size of our classroom, then an average virus would be the size of a softball.
Prokaryotes
Eukaryotes
Viruses
Eukaryotic Nucleus
1 ųm (1000 nm)

11. Viral Size

12. Specificity: viruses are highly specific to the cells they infect Examples: 1) plant viruses infect plant cells 2) animal viruses infect only certain related species of animals 3) bacterial viruses (bacteriophage) infect only certain types of bacteria.
So, what about zombies?

13. Write this on your notes!
- Retroviruses: contain RNA instead of DNA. The RNA is copied backward, from RNA to DNA. - HIV is a retrovirus you will need to know.
AZT is a medication used to treat HIV by stopping an enzyme called reverse transcriptase
Write this on your notes!

14. Think-Pair-Share
Are viruses alive?
(Justify your answer)

15. Viruses are parasites (use other organisms to grow and reproduce)
Viruses are parasites (use other organisms to grow and reproduce) Viruses are NOT alive because they do not: a) grow and develop b) obtain and use energy (metabolism) c) respond to the environment d) consist of cells

16. Vaccines. 1. Viral diseases cannot be treated with antibiotics. 2
Vaccines 1. Viral diseases cannot be treated with antibiotics. 2. Vaccines are the best way to protect against viruses a) A vaccine is a dead or weakened version of a virus b) Vaccines provide protection only if they are used before an infection begins.

17. Most viruses are not harmful to humans. 1
Most viruses are not harmful to humans. 1. A pathogen is a disease-causing agent. 2. Viruses cause disease by disrupting the body’s normal equilibrium or homeostasis. 3. Viruses attack and destroy certain cells in the body, causing the symptoms of the disease.