All Life Cycles

Question 1

General life cycle of animal virus
6 steps

Answer 1

1. Attachment
2. Penetration (by endocytosis or fusion)
3. Uncoating
4. Biosynthesis (infected host cells produces nucleic acid and viral proteins)
   • MAY REQUIRE VIRAL ENZYMES ***
5. Maturation or Assembly
6. Release (by budding (if enveloped), exocytosis, or rupture lysis)

Question 2

HPV: DNA Genome
6 Steps of Cycle

Answer 2

1. Attachment and Endocytose
2. Vision travels to nucleus
3. Viral genome is uncoated
4. Biosynthesis: DNA his transcribed (nucleus) and translated (cytoplasm), producing capsid
5. Assembly in nucleus
6. Release :virions shed off as epithelial cells (slough)

Question 3

Influenza A Virus REPLICATION Cycle
6 steps

Answer 3

1. Attachment
2. Penetration
3. Uncoating
4. Biosynthesis
5. Assembly
6. Release

Question 4

Influenza A LIFE Cycle
10 steps

Answer 4

1. Binding to silica acid on host glycoprotein receptors
2. Endocytosis, endosome membrane fuses with envelope, genome uncoated
   3.(-) RNA released with RDRP
3. (-) RNA copied to (+) RNA by viral (RdRp)
   5.(+) RNA translated, produces proteins (capsid, RNA polymerase, envelope proteins)
4. (+) RNA copied to (-) RNA by RdRp —> replication
5. Genome and RdRP packaged with nucleocapsid and matrix
6. Proteins inserted into host membrane
7. Virus particles envelope through budding
8. Release of virus particles destroy host cell

Question 5

Draw HIV genome
Describe:
Gag
Pol
Env

Answer 5

*Look at ppt for genome drawing *
gag: capsid, nucleocapsid, matrix
Pol: integrate, reverse transcriptase,protease
Env: encodes envelope proteins

Question 6

Phagocytosis
5 steps:

Answer 6

1. Attachment - bacterium binds to phagocytes cell surface. Antibody and complement aid in binding
2. Pseudopods extend and engulf organism
3. Invagination of membrane, traps organisms in phagosome
4. Lysosome fuses and deposits enzymes into phagosome. Enzymes cleave macromolecules, generate reactive oxygen
5. Organisms destroyed.

Question 7

Phases of phagocytosis
7 steps:

Answer 7

1. Chemotaxis and adherence of microbe to phagocyte
   • MAMP’s and TLR’s
2. Ingestion of microbe by phagocyte
   • Pseudopods
3. Formation of Phagosome
4. Fusion of phagosome and lysosome
   • phagolysosome
5. Digestion of microbe by enzymes
6. Formation of residual body containing indigestible material
7. Discharge of waste

Question 8

Generalized transduction (5 steps)

Answer 8

1. phage infects donor cell
2. Phage DNA and proteins are made, bacterial chromosome broken into pieces
3. Assembly, bacterial DNA is packaged into capsid. Donor cell lyses and releases phage particles that contain DNA
4. Phage carrying DNA infects new host (recipient cell)
5. Recombination (recombinant cell with a genotype different from both recipient cells)

Question 9

Specialized transduction (6 steps)

Answer 9

1. Prophage exists in galactose (containing gaf gene)
2. Phage genome excises, camping with adjacent gaf gene
3. Phage matures, cell lyses, releasing phage with gaf gene
4. Phage infects cell that cannot utilize galactose (lacking gaf gene)
5. Bacterial gaf gene integrates into new hosts DNA
6. Lysogenic cell can now metabolize glucose

Question 10

Conjugation (6 steps)

Answer 10

1. Sex plus from ft plasmid donor (left) attaches to recipient (right)
2. Contraction occurs drawing 2 cells together, protein bridge forms
3. F factor nicked at Ori T, 5’ end begins transfer
4. Strand remaining is replicated
5. Transfer brand circulate and replicates as well
6. Recipient converted to donor

Question 11

Viral Life Cycle
5 steps

Answer 11

1. Recognition/attachment
2. Entry
3. Biosynthesis
4. Assembly of Virion
5. Exit and transmission

Question 12

Lytic life cycle
5 steps

Answer 12

1. Attachment
2. Penetration
3. Biosynthesis
4. Maturations
5. Release

Question 13

Lysogenic life cycle
5 steps

Answer 13

1. Attachment
2. Penetration
3. Integration
4. Excision (stimulated by UV or chemicals)
5. Lytic cycle