Summary samenvatting human infecious diseases

A snapshot of the summary - samenvatting human infecious diseases

• 1 Lecture 1 + 2

• What is a virus?

  The smallest genetic entities. 
  A piece of genetic information with a protein coat that hijacks' the host cells and replicates itself
• What are the 3 main characteristics of viruses?

  1. Infectivity 
  • penetrate and multiply in host cell 
  2. Obligate intracellular parasite 
  • cannot replicate by itself, no protein synthesizing machinery or energy producing machinery 
  3. property to survive outside a living cell in an extracellular state 
  • in an inert state or via carrier, depends on environment 
• A virus is composed of

  • Nucleic acid 
    
  • RNA or DNA 
  • SS or DS 
  • segmented or non segmented 
  • protein shell 
  • assembled form smaller subunits: coat proteins 
  • lipid membrane / viral envelope 
  • some viruses
  • made from host cell 
• All viral RNA genomes are __1__ (linear/circular) except for __2__

  1 = Linear
  2 = viroids
• The properties of the viral genetic material depends on

  The family to which the virus belongs
• The minimal virus needs the 2 genes:

  1. DNA/RNA-polymerase
     
  • multiplication of RNA or DNA genome 
  2. coat protein
  • protection and host interaction 
• The viral genomes varies between (nucleotideS)

  2,000 - 1,000,000
• What is mutation rate

  The number of necleotides per 1000 nt of genome length that mutate per year
• What affects the mutation rate?

  • The nature of the genetic material 
    
  • RNA viruses mutate quicker than DNA viruses
    
  • number of generation per year 
• Why do RNA viruses mutate quicker than DNA viruses

  DNA polymerase has proofreading whereas RNA polymerase doesn't