slide1
Download
Skip this Video
Download Presentation
Figure 10.22

Loading in 2 Seconds...

play fullscreen
1 / 20

Figure 10.22 - PowerPoint PPT Presentation


  • 133 Views
  • Uploaded on

Figure 10.22. VIRUSES: GENES IN PACKAGES. Viruses Components Infection cycle 3. DNA, RNA viruses 4. Uses of viruses. Components of a virus (phage). 1. Protein coat = capsid 2.genetic material DNA or RNA 3. enzyme. Components of a virus. Membranous envelope. envelope capsid

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha
Download Presentation

PowerPoint Slideshow about 'Figure 10.22' - tegan


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.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript
slide2

VIRUSES: GENES IN PACKAGES

Viruses

Components

Infection cycle

3. DNA, RNA viruses

4. Uses of viruses

slide3

Components of a virus (phage)

1. Protein coat = capsid

2.genetic material

DNA or RNA

3. enzyme

components of a virus
Components of a virus

Membranousenvelope

  • envelope
  • capsid
  • genetic material
    • Ex. flu viruses

RNA

Proteincoat

Glycoprotein spike

Figure 10.18A

slide5
Phage reproductive cycle

Phage DNA directs host cell to make more phage DNA and protein parts. New phages assemble.

Phage attaches to bacterial cell.

Phage injects DNA.

Cell lyses and releases new phages.

viral dna may become part of the host chromosome
Viral DNA may become part of the host chromosome

Phage

Attachesto cell

Bacterialchromosome

Phage DNA

Cell lyses,releasing phages

Phage injects DNA

Many celldivisions

Occasionally a prophagemay leave the bacterialchromosome

LYTIC CYCLE

LYSOGENIC CYCLE

Phagesassemble

Phage DNAcircularizes

Lysogenic bacteriumreproduces normally,replicating the prophageat each cell division

Prophage

OR

New phage DNA andproteins are synthesized

Phage DNA inserts into the bacterialchromosome by recombination

slide7

Glycoprotein spike

VIRUS

Protein coat

Viral RNA(genome)

Envelope

Plasmamembraneof hostcell

Entry

1

Uncoating

2

  • Viruses redirect the host cell machinery to make more viruses
  • Some animal viruses steal a bit of the host cell’s membrane

Viral RNA(genome)

RNA synthesisby viral enzyme

3

Proteinsynthesis

RNA synthesis(other strand)

5

4

mRNA

Template

New viral

genome

Newviral protein

Newviral proteins

Assembly

6

Exit

7

Figure 10.18B

plant viruses are serious agricultural pests
Plant viruses are serious agricultural pests
  • Most plant viruses have RNA
    • Example: tobacco mosaic disease

Protein

RNA

Figure 10.19

slide9
The deadly Ebola virus causes hemorrhagic fever
    • Each virus is an enveloped thread of protein-coated RNA
  • Hantavirus is another enveloped RNA virus
  • SARS - coronavirus
  • Avian flu

Figure 10.20A, B

slide13
HIV infection

Figure 10.22x1

slide14
AIDS quilt

Figure 10.22x2

uses of viruses
Uses of Viruses
  • Pest control
  • Vaccines
  • Anti-cancer treatment
  • Gene therapy
anti cancer viruses
Anti-cancer viruses

Makes use of viral ability to enter only cells of one type

Allows targeting of therapy to tumor cells

Enables identification of small tumor sites

other parasitic particles
Other parasitic particles
  • Viroids - infectious RNA (no capsid)
  • Prions - infectious protein
    • Cellular PrP, prion PrP
    • Spongiform encephalopathies cause neural degeneration
ad