Chapter 13,part A Viruses,Viroids,and Prions
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings B.E Pruitt & Jane J. Stein Chapter 13, part A Viruses, Viroids, and Prions
Viruses Viruses contain DNA or RNA 。And a protein coat Some are enclosed by an envelope 。 Some viruses have spikes Most viruses infect only specific types of cells in one host Host range is determined by specific host attachment sites and cellular factors
Viruses • Viruses contain DNA or RNA • And a protein coat • Some are enclosed by an envelope • Some viruses have spikes • Most viruses infect only specific types of cells in one host • Host range is determined by specific host attachment sites and cellular factors
Viruses 225nm Human red Bacteriophage T4 Rabies virus blood cell 章 170×70nm 10,000nm in diameter Adenovirus 90 nm Rhinovirus Bacteriophage M13 30 nm 800×10nm Chlamydia elementary body 300nm Bacteriophages Tobacco mosaic virus 2,MS2 250×18nm 24 nm Viroid 300×10nm Prion Poliovirus 200×20nm 30 nm Vaccinia virus Ebola virus 300×200×100nm 970nm E.coli Plasma membrane (a bacterium) of red blood cell 3000×1000nm 10 nm thick Figure 13.1
Viruses Figure 13.1
Helical Viruses Nucleic acid Capsomere Capsid (a)A helical virus (b)Ebola virus Figure 13.4a,b
Helical Viruses Figure 13.4a, b
Polyhedral Viruses Capsomere Nucleic acid Capsid (a)A polyhedral virus (b)A Mastadenovirus Figure 13.2a,b
Polyhedral Viruses Figure 13.2a, b