1 / 7

Chapter 27

Chapter 27. Viruses Joe Ganoe Jesus Trochez. Types of Viruses. Plant Virus Helical capsid shape Animal Virus Icosahedral capsid Bacterial Virus Icosahedral head : helical tail Animal Virus Helical capsid within envelope. Lytic Cycle. Reproductive virus cycle 5 step process

collin
Download Presentation

Chapter 27

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. Chapter 27 Viruses Joe Ganoe Jesus Trochez

  2. Types of Viruses • Plant Virus • Helical capsid shape • Animal Virus • Icosahedral capsid • Bacterial Virus • Icosahedral head : helical tail • Animal Virus • Helical capsid within envelope

  3. Lytic Cycle • Reproductive virus cycle • 5 step process • Attachment • Penetration • Synthesis • Assembly • Release

  4. Lytic Cycle Steps • Attachment • Virus attaches to cell wall • Penetration • Viral DNA injected into cell • Synthesis • Protein and nucleic acid form • Assembly • Involves spontaneous assembly of capsid and enzyme to insert DNA • Release • Lysis (disintegration of cell by rupture of its plasma membrane) of cell

  5. Lysogenic Cycle • 3 Step process • Intergration • Propagation • Induction • Starts at the 2nd cycle of the Lytic Cycle (Penetration) • After it ends the virus returns to Synthesis in the Lytic Cycle • This cycle does not immediately kill the cells they infect, but use the cell to make it into another virus cell

  6. Lysogenic cycle • Integration • Integration of genome leads to prophage • Propagation • Propagation of prophage along with host genome • Induction • Induction prophage exits the bacterial chromosome, viral genes are expressed

  7. Key Terms • Lytic cycle • A viral cycle in which the host cell is killed (lyse) by the virus after viral duplication to release viral particles • Lysogenic Cycle • A viral cycle in which the viral DNA becomes integrated into the host chromosome and it replicated during cell reproduction. Results in vertical rather than horizontal transmission • Bacteriophage • A virus that infects bacterial cells • Also called a phage • Capsid • The outermost protein covering a virus • Tissue Tropism • The affinity of a virus fro certain cells with a multicellular host • For example, hepatitis B virus targets liver cells. • Host range • that can be infected by a particular virus • Icosahedron • A structure consisting of 20 equilateral triangular facets • This is commonly seen in viruses and forms one kind of viral capsid • Phage conversion • The range of organismsthe phenomenon by which DNA forma virus, incorporated into a host cell’s genome, alters the host cell’s function in a significant way • Envelope • A casing that protects the virus from being attacked. Only found in animal cells.

More Related