Viruses

• Are viruses living things?

  NO!
• What do viruses do that living things do?


  Reproduce very rapidly
• Capsid of viruses are protein structures that protect the genetic material from damage
• Viruses can have DNA or RNA
• Bacteriophages infect prokaryotic cells (bacteria)
• What is the shortest reproductive cycle of a virus?

  Lytic cycle
• Steps of the lytic cycle:

  1: Virus attachment

  2: DNA/RNA insertion

  3: Host DNA disrupted

  4: Virus replication and assembly

  5: LYSIS
• Steps of the lysogenic cycle:

  1: Virus attachment

  2: DNA/RNA insertion

  3: Virus integrates itself with host DNA

  4:Viral DNA replicated by mitosis

  5: Stress and environment trigger lytic cycle
• When do you start to feel symptoms of a viral infection?


  When body cells are destroyed
• Virus transmissions: Blood-borne, fecal-oral, respiratory, sexual, and animal vectors
• Retroviruses convert their RNA into DNA so it can join host DNA
• Viruses are parasites that can only reproduce inside a host cell