Foundations-Cells-3

From CellBiology

Introduction to Viruses and Prions


This lecture is also an introduction to cell compartments and describes the structure of membranes forming these compartments.


Draft - this online lecture is currently in 2018 draft status. This notice removed when completed.
Cells and Membranes: 1 Cells and sizes | 2 Prokaryotes | 3 Viruses and prions | 4 Plasma membrane | 5 Compartments | 6 Membrane structure | 7 Membrane specialisations | Foundations - Moodle

Terms

  • Bacteriophage - A virus that infects bacteria.
  • Prion -
  • Virion - virus particle, the infective agent, contains the genetic material, DNA or RNA within a protective protein coat (capsid)
  • Virus - a non-living infective agent of living cells.

Virus

  • single compartment, no membranes
  • not alive, infects living cells (Latin, virus = toxin or poison)
  • unable to grow or reproduce outside a host cell
  • Infect different hosts (animal, plant and bacterial)
  • Classified - RNA or DNA viruses; double or single stranded



A nanometer is one thousand millionth of a metre. (1 x 10-9)

Zika virus

Zika virus (scale bar 40 nanometers)

Herpes virus - CDC electron micrograph

Herpes virus



Viral Infection - Made Easy 


Flu Attack! How A Virus Invades Your Body (Published on Oct 23, 2009) A simplified demonstration of viruses and cells. This is an airborne respiratory virus and how it infects the respiratory epithelium during a Flu infection.

Simple terms used in the above video explained.

  • Key - viral ligand. Pretends to be a molecule that the cell would normally recognise.
  • Lock - cell receptor.
  • Pink molecule - DNA replication.
  • Blue - ribosome.
Links: MCB - Viruses: Structure, Function, and Uses | MCB - Retroviral life cycle | NPR - Virus Infection | Foodbourne Illness | International Committee on Taxonomy of Viruses

Prion

  • an infectious prion protein, no compartments, no membrane
  • not alive, misfolded normal protein (three-dimensional structure), can form aggregates


  • Creutzfeldt-Jacob disease (CJD) and Kuru a human neural prion disease
  • Variant Creutzfeldt-Jakob disease (vCJD) Brain caused by consumption of food of bovine origin contaminated with the agent of Bovine Spongiform Encephalopathy (BSE).
  • Bovine spongiform encephalopathyvery (BSE) in cattle, "mad cow disease"
  • Scrapie in sheep




Links: Creutzfeldt-Jakob disease | Molecular Biology of the Cell Figure 6-89. Protein aggregates that cause human disease | Prions Are Infectious Proteins | Gene Reviews Prions | Neuroscience Prion Disease
VCJD brain.png

Variant Creutzfeldt-Jakob disease (vCJD) Brain



Draft - this online lecture is currently in 2018 draft status. This notice removed when completed.
Cells and Membranes: 1 Cells and sizes | 2 Prokaryotes | 3 Viruses and prions | 4 Plasma membrane | 5 Compartments | 6 Membrane structure | 7 Membrane specialisations | Foundations - Moodle