EBio - notes5 - Bacteria Virus Gene 11-29A

EBio - notes5 - Bacteria Virus Gene 11-29A - Chapter 18 The...

Info iconThis preview shows pages 1–15. Sign up to view the full content.

View Full Document Right Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: Chapter 18 The Genetics of Viruses and Bacteria QUESTIONS? Overview: Microbial Model Systems Viruses called bacteriophages can infect bacteria, such as Escherichia coli E. coli and its viruses are called model systems Viruses and bacteria have unique genetic mechanisms that are interesting in their own right LE 18-2 Virus Bacterium Animal cell Animal cell nucleus 0.25 m Concept 18.1: A virus has a genome but can reproduce only within a host cell Scientists detected viruses indirectly long before they could see them The story of how viruses were discovered begins in the late 1800s The Discovery of Viruses: Scientific Inquiry Tobacco mosaic disease stunts growth of tobacco plants and gives their leaves a mosaic coloration In the late 1800s, researchers hypothesized that a particle smaller than bacteria caused the disease In 1935, Wendell Stanley confirmed this hypothesis by crystallizing the infectious particle, now known as tobacco mosaic virus (TMV) Structure of Viruses Viruses are not cells Viruses are very small infectious particles consisting of nucleic acid enclosed in a protein coat and, in some cases, a membranous envelope Viral Genomes Viral genomes may consist of Double- or single-stranded DNA Double- or single-stranded RNA Depending on its type of nucleic acid, a virus is called a DNA virus or an RNA virus Capsids and Envelopes A capsid i s the protein shell that encloses the viral genome A capsid can have various structures LE 18-4a Capsomere of capsid RNA 18 250 mm Tobacco mosaic virus 20 nm LE 18-4b Capsomere Glycoprotein 7090 nm (diameter) DNA Adenoviruses 50 nm Some viruses have membranous envelopes that help them infect hosts These viral envelopes surround the capsids of influenza viruses and many other viruses found in animals Viral envelopes, which are derived from the host cells membrane, contain a combination of viral and host cell molecules LE 18-4c Glycoprotein 80200 nm (diameter) RNA Capsid Influenza viruses 50 nm Membranous envelope...
View Full Document

This note was uploaded on 02/28/2008 for the course EBIO 1210 taught by Professor Demmig-adam during the Fall '07 term at Colorado.

Page1 / 35

EBio - notes5 - Bacteria Virus Gene 11-29A - Chapter 18 The...

This preview shows document pages 1 - 15. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online