Viruses: Chapter 5 - Biology - PDF

Viruses Chapter 5 1  t IT iTti chromosome genomic material chromosome...

Viruses Chapter 5 1  t IT iTti chromosome genomic material chromosome nucleus nucleocapsid nucleiod Chromosome made DNA or RNA Chromosome made of DNA doublestranded of DNA double stranded or single double stranded Do not have cell membrane cell membrane A membrane some have a cell membrane 10 404 Ultra 604 100 Light electromycrosopy microscope histtoscope probe microsopy Phage Bacteria could infect bacteria Any cell can be infected by a virus Donothaveribosomenucleicacids Host range Tropism Bacteriophage 2 Viruses “microbes” Acellular Obligate intracellular parasites Very small ELECTRON MICROSCOPY 10-100 nm “ultramicroscopic” Genomic material is not always DNA! different virusis have differentgenomic DNA TRANSMISSION SCANNING 3 Viral structure acid Capsid proteinthat protectsNullenic Helical Icosahedral Genome RNA or DNA protein Single- or double-stranded Linear, circular, segmented e it trandedDWA Nucleocapsid singlestranded DNA doubstranded RNA payload singlestrandedRNA 4 Virion virus Viral structure Attachment (glyco)proteins Accessory proteins Neonvolope Envelope or naked RNA to RNA needs RNApolymera 5 Entry - Animal Entdocitosis Bacteria 6 Replication Virus infection 1. Attach 2. Enter 3. Synthesis make Genome protein f Protein 4. Assembly 5. Release iftheydont Permissive cell Yet Host range/tropism Burst size/burst time 7  Animal Viruses Can fall into any genomic category Most human pathogens = RNA 4 different infection outcomes Acute 1. arm (acute) infection Virulent 2. Persistent (chronic) infection 3. Latent infection 4. Transformation 8  cant For HIV 1 Afflesistent Chronic Time Latent HHVs HPV Warts does gotaway cancers causelancer HPV 16,18 Transformation cervical cancer Entry – other Bacteria Phage Defvering DNA 9  specifisacteria Lytic v. lysogeny (Phage) 10 Measuring phage titers can grow viruses on agar Plaque assay hopes Lytic 11 Animal virus titers Plaque assay Cytopathic effect (CPE) TCID50 Hemagglutination 12  SSDNA dsDNA Viral Diversity dsRNA SSRNA I C T V = International Committee on Taxonomy of Viruses Classify viruses based on Order, Family, Subfamily, Genus, and Species classify viruses getsystem Baltimore BaseefenEc Genomic-based Seven categories SSRNA peter transcitatesDNA 13 Viroids RNA prions proteins infection to RNA only work in plants  prions aomone Virus-like particles infectious proteins Viroids RNA Plant pathogen Enter through a wound RNA replicase dsRNA – Rnases Interferes with regulatory RNA 14 Virus-like ooooparticles Prions Ingest onprotein Protein Spongeform encephalopathy Scrapie (sheep) Mad cow (BSE) Chronic wasting disease (elk & deer) Kuru (people) Creutzfeldt-Jakob Disease (people) 15 Virus-like particles Satellite viruses Need another virus for infection HepD 16