dsDNA SSDNA 念 Maior Myoviridae, isometric head Bacteriophage Inoviridae Families and Myoviridae, elongated head enera Siphoviridae 和 Podoviridae The Myoviridae are Lipothrixvinidae SNDv-like viruse the only family with Inoviridae contractile tails lasmaviridae Corticoviridae Plasmaviridae are pleomorphiC Fusellovinidae Tectiviridae have RL rudiviridae distinctive double dsRNA SSRNA capsids whereas the corticoviridae have Cystoviridae Levivinidae complex capsids 100nm containing lipid
Major Bacteriaophage Families and Genera. The Myoviridae are the only family with contractile tails. Plasmaviridae are pleomorphic. Tectiviridae have distinctive double capsids, whereas the corticoviridae have complex capsids containing lipid
Viruses can exist in two phases extracellular and intracellular Virion, the extracellular phase, posses few if any enzymes and can not reproduce independently of living cells. In the intracellular phase, viruses exist primarily as replicating nucleic acids that induce host metabolism to synthesize virion components; eventually complete virus particles or virions are released
Virion, the extracellular phase, posses few if any enzymes and can not reproduce independently of living cells. In the intracellular phase, viruses exist primarily as replicating nucleic acids that induce host metabolism to synthesize virion components; eventually complete virus particles or virions are released. extracellular and intracellular Viruses can exist in two phases
Hosts and size Three main classes -animal viruses. bacterial viruses (bacteriophages), and plant viruses The particular host range of a virus is determined by the virus's requirements for its specific attachment to the host cell and the availability within the potential host of cellular factors required for viral multiplication Virus particles(virions) vary widely in size and shape. Viruses are smaller than cells, ranging in size from 0.02 to 0.3 um. A common unit of measure for viruses is the nanometer which is 1000 times smaller than 1 um and 1 million times smaller than 1 mm. Smallpox virus, one of the largest viruses, is about 200 nm in diameter(a bit smaller than the size of the smallest bacteria); poliovirus, one of the smallest, is only 28 nm in diameter (about the size of a ribosome)
Hosts and size Three main classes - animal viruses, bacterial viruses (bacteriophages), and plant viruses. The particular host range of a virus is determined by the virus's requirements for its specific attachment to the host cell and the availability within the potential host of cellular factors required for viral multiplication. Virus particles (virions) vary widely in size and shape. Viruses are smaller than cells, ranging in size from 0.02 to 0.3 μm. A common unit of measure for viruses is the nanometer, which is 1000 times smaller than 1 um and 1 million times smaller than 1 mm. Smallpox virus, one of the largest viruses, is about 200 nm in diameter (a bit smaller than the size of the smallest bacteria); poliovirus, one of the smallest, is only 28 nm in diameter (about the size of a ribosome)
The comparative sizes of several viruses and bacteria 225 no Hacterachase MIs H.Ern MOnr x TUnn e 24 nm Totacromasie vius Bacterin 2n x 18 n b实m(k3xm ●3nm poliovirus wacana viru 3. nm x 20nm x ICD nm Pe-nerete ot bleed ell L crit il r emic hater
The comparative sizes of several viruses and bacteria:
Structure of viruses Most viruses are too small to be seen under light microscope. All viruses consists of an rNa or dNa core genome surrounded by a protein coat id capsic The combined viral genome and capsid is called the nucleocapsid. .The nucleic acid of a virus is surrounded by a protein coat called the capsid .Each capsid is composed of protein subunits called capsomeres .In some viruses, the capsid is covered by an envelope, which usually consists of some combination of lipids, proteins, and carbohydrates. .Depending on the virus, envelopes may or may not be covered by spikes, which are carbohydrateprotein complexes that project from the surface of the envelope
• Most viruses are too small to be seen under light microscope. • All viruses consists of an RNA or DNA core genome surrounded by a protein coat capsid. • The combined viral genome and capsid is called the nucleocapsid. •The nucleic acid of a virus is surrounded by a protein coat called the capsid •Each capsid is composed of protein subunits called capsomeres. •In some viruses, the capsid is covered by an envelope, which usually consists of some combination of lipids, proteins, and carbohydrates. •Depending on the virus, envelopes may or may not be covered by spikes, which are carbohydrateprotein complexes that project from the surface of the envelope. Structure of viruses