1. Viruses

2. Characteristics Size - ~20nm – 250nm Some char. of life, not all:
- no nucleus, cytoplasm, organelles, or membrane
- no cellular functions
- need a host cell to reproduce

4. Structure Made of : 1. Nucleic Acid (DNA or RNA)
2. Protein coat around it (capsid)
Some also have:
- lipid envelope outside capsid
*helps it infect cell
- glycoprotein – used to attach to host cell

5. Replication Lytic cycle – virulent (kills cell) 1. Attachment
2. Injection of NA
3. Replication
4. Assembly
5. Release of new viruses (burst cell)

6. Lysogenic cycle – temperate (lives with host)
1. Attachment
2. Injection
3. Integration of DNA
4. Cell Multiplication
Can revert to lytic