Chapter 13,part B Viruses,Viroids,and Prions
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings B.E Pruitt & Jane J. Stein Chapter 13, part B Viruses, Viroids, and Prions
Attachment.Penetration. and Uncoating Plasma membrane Vesicle of host cell (a)Attachment (b)Endocytosis (c)Penetration (d)Uncoating Figure 13.14
Attachment, Penetration, and Uncoating Figure 13.14
Release of an enveloped virus by budding Viral capsid Host cell plasma membrane Viral protein Bud Bud Envelope (a)Release by budding (b)Alphavirus Figure 13.20
Release of an enveloped virus by budding Figure 13.20
Multiplication of DNA Virus Papovavirus Virion attaches to host cell ⑦Virions are released Host cell DNA Capsid DNA 2 Virion penetrates ⑥Virions mature cell and its DNA is Cytoplasm uncoated Capsid proteins mRNA ⑤Late translation: capsid proteins are synthesized 4 3 Early transcription and Late transcription; DNA is replicated translation;enzymes are synthesized Figure 13.15
Multiplication of DNA Virus Figure 13.15 Virion attaches to host cell Virion penetrates cell and its DNA is uncoated Early transcription and translation; enzymes are synthesized 1 2 3 DNA Late transcription; DNA is replicated 4 Late translation; capsid proteins are synthesized 5 6 Virions mature Capsid Papovavirus Host cell DNA Cytoplasm 7 Virions are released Capsid proteins mRNA
Pathways of Multiplication for RNA-Containing Viruses Attachment Capsid、 Nucleus RNA Host -Cytoplasm cell Maturation Penetration and Release and Uncoating Translation and Synthesis RNA Rep lication of Viral Proteins Viral- (a): strand mRNA is ed m the The+strand(mRNA)must firs strand. be transcribed from the-viral ore proteins can tein into capsid om mN Key: dsRNA that is incorporated as new viral genome. Viral genome 厂+or sense strand of viral genome -or antisense strand of viral genome Capsid proteins mRNA is produced inside the ss single-stranded and RNA- and ds=double-stranded NApoiymerase Figure 13.17
Pathways of Multiplication for RNA-Containing Viruses Figure 13.17