第9-1章微生物学(赵立平).pdf

Virus: Growth, quantification, replication and diversity Lecture 9-1 Essentials of Virology CHAPTER 10 in BROCK BIOLOGY OF MICROORGANISMS School of Life Science and Biotechnology, Shanghai Jiao Tong University Shanghai Jiao Tong University What is a virus? One type of genetic elements • Nucleic acid Replication independent of a cell’s chromosome复制独立于细胞的染色体 • Multiplication dependent on host cell’s metabolism繁殖依赖于细胞的代谢 • Have Extracellular state-virus particles有胞外 形式(病毒粒子) Shanghai Jiao Tong University Shanghai Jiao Tong University Differences between virus and plasmid? Virus has extracellular state, plasmid does not Virus can cause cell lysis, plasmid does not ………………….. Shanghai Jiao Tong University Shanghai Jiao Tong University I. VIRUS AND VIRION 9.1 General Properties of Viruses 9.2 Nature of the virion Shanghai Jiao Tong University Shanghai Jiao Tong University 9.1 General properties of viruses Extracellular state胞外形式 • Is a minute particle containing nucleic acid surrounded by protein (and occasionally, containing other macromolecular components) • Virus particle/virion: metabolically inert毒粒:代谢隋性 Intracellular state胞内形式 • Virus Replication occurs: New copies of virus genome are produced, and the virus coat components are synthesized. • Infection : the process when a virus genome is introduced into a host cell and reproduces感染 Shanghai Jiao Tong University 9.1.1 Types of Viral Genomes The genomes of viruses: DNA or RNA, and some use both as their genomic material at different stages in their li