Phages and Other Viruses

Card Set Information

Phages and Other Viruses
2013-08-01 11:37:28
Biology GRE

Biology GRE
Show Answers:

  1. Viruses
    • Rely on host to replicate
    • have no organelles or cells
  2. Capsid
    • Protein shell that surrounds virus
    • Most also have sugars (glycoproteins) that are attached and stick out of the capsid, which help them gain entry to a living cells by binding with surface proteins on cell membrane
  3. Viral Envelope
    • Some viruses are able to surround themselves with an envelope of a cells membrane when they burst out o an infected cell (Lysee)
    • Helps avoid detection of host because it appears as a hosts own cell
  4. Lytic Cycle
    • Attachment and penetration
    • Uncoating
    • viral mRNA protein synthesis
    • Replication of the genome
    • Assembly and release
  5. Attachment and Penetration
    • The type of proteins in capsid determine how many cells a virus can infect
    • Attach using glycoproteins
  6. Uncoating
    • As a particle penetrates the cell traps it in a vesicle
    • Capsid breaks and vesicle dumps the genetic material into cytoplasm
  7. Viral mRNA Protein Synthesis
    • DNA virus replicate in cells nucleus with RNA poly
    • RNA virus replicate in cytoplasm
  8. Retrovirus
    • RNA virus' ex:HIV
    • Converts RNA-->DNA using enzyme Reverse transcritase and then DNA back to RNA
  9. Enzyme Reverse Transcritase
    • Converts RNA-->DNA
    • Reverse Transcription
  10. Replication of the Genome
    • All viruses will first replicate DNA/RNA they started with 
    • Then the copies replicate further 
    • Similar to making a negative of a photo and then using a negative to make more photos instead of the photo itself
  11. Assembly
    • Viral Nucleic acid is package with in capsid
    • Baby viruses are released from cell slowly or all at once
    • Slowly they bud out of the cell, all at one it ruptures and kills the host cell
  12. Lysogenic Cycle
    Viral DNA gets integrated into host cells DNA
  13. Bacteriophages
    • Viruses that infect bacteria
    • Have tail and tail fibers 

  14. Lytic Vs lysogenic
  15. Restriction Enzymes
    Powerful bacterial enzymes that digest viral DNA/RNA
  16. Lytic Phages
    Phages that infect in lytic fashion
  17. Temperate Phages
    • Phages that infect bacteria in a lysogenic way
    • Integrate DNA/RNA
  18. Viroids
    • Virus like particles composed of single molecule of circular RNA without capsid
    • Implicated in plant diseases
  19. Prions
    • Infectious proteins
    • Take years for symptoms to develop
    • NO DNA/RNA
    • Change structure of normal proteins by switching to non encoding genes