Medical Virology Dept. of Medical Microbiology and Parasitology Shanghai second Medical University Shanghai, China E mail:(xkguo( shamu.edu. cn
Medical Virology Dept. of Medical Microbiology and Parasitology Shanghai Second Medical University Shanghai, China. E.mail: ( xkguo@shsmu.edu.cn )
General virology Conception Viruses l Virion SIze and shape Structure Replication Viral variation Classification
General Virology ◼Conception ◼Viruses ◼Virion ◼Size and Shape ◼Structure ◼Replication ◼Viral Variation ◼ Classification
Conception a Virology is the bioscience for study of viral nature, and the relationship between viruses and hosts Viruses often cause serious diseases. relate to some cancers and congenital deformities. also can be used as tool for genetic engineering
Conception ◼ Virology is the bioscience for study of viral nature,and the relationship between viruses and hosts. Viruses often cause serious diseases, relate to some cancers and congenital deformities, also can be used as tool for genetic engineering
3000BC
◼ 3000BC
History mallpox was endemic in China by 1000BC. In response the practice of variolation was developed. Recognizing that survivors of smallpox outbreaks were protected from subsequent infection. variolation involved inhalation of the dried crusts from smallpox lesions like snuff, or in later modifications inoculation of the pus from a lesion into a scratch on the forearm of a child
History ◼ Smallpox was endemic in China by 1000BC. In response, the practice of variolation was developed. Recognizing that survivors of smallpox outbreaks were protected from subsequent infection, variolation involved inhalation of the dried crusts from smallpox lesions like snuff, or in later modifications, inoculation of the pus from a lesion into a scratch on the forearm of a child
Definitionof virus Viruses may be defined as acellular organisms whose genomes consist of nucleic acid, and which obligately replicate inside host cells using host meta bolic machinery and ribosomes to form a pool of components which assemble into particles called VIRIONS, which serve to protect the genome and to transfer it to other cells
Definition of Virus Viruses may be defined as acellular organisms whose genomes consist of nucleic acid, and which obligately replicate inside host cells using host metabolic machinery and ribosomes to form a pool of components which assemble into particles called VIRIONS, which serve to protect the genome and to transfer it to other cells
Viral Properties Viruses are inert (nucleoprotein )filterable gents Viruses are obligate intracellular parasites Viruses cannot make energy or proteins independent of a host cell Viral genome are rna or dna but not both. Viruses have a naked capsid or envelope with attached proteins Viruses do not have the genetic capability to multiply by division. Viruses are non-living entities
Viral Properties ◼ Viruses are inert (nucleoprotein ) filterable Agents ◼ Viruses are obligate intracellular parasites ◼ Viruses cannot make energy or proteins independent of a host cell ◼ Viral genome are RNA or DNA but not both. ◼ Viruses have a naked capsid or envelope with attached proteins ◼ Viruses do not have the genetic capability to multiply by division. ◼ Viruses are non-living entities
Consequences of properties Viruses are not living a Viruses must be infectious to endure in nature Viruses must be a ble to use host cell processes to produce their components(viral messenger RNA, protein, and identical copies of the enome Viruses must encode any required processes not provided by the cell Viral components must self-assemble
Consequences of Viral Properties ◼ Viruses are not living ◼ Viruses must be infectious to endure in nature ◼ Viruses must be able to use host cell processes to produce their components (viral messenger RNA, protein, and identical copies of the genome) ◼ Viruses must encode any required processes not provided by the cell ◼ Viral components must self-assemble
Challenges the way we define life viruses do not respire nor do they display irritability应急性; they do not move they do not grow they do most certainly reproduce, and may adapt to new hosts
Challenges the way we define life ◼ viruses do not respire, ◼ nor do they display irritability应急性; ◼ they do not move ◼ they do not grow ◼ they do most certainly reproduce, and may adapt to new hosts
Size and shape Methods Size of viruses Shapes of viruses
Size and Shape ◼ Methods ◼ Size of Viruses ◼ Shapes of Viruses