Transcript How are bacteria different from viruses?

Warm-up:
Describe a time in your life when you
were really sick.
Do you know if you had a virus or a
bacterial infection (maybe it was
something else!)
What were the symptoms and how
was it treated?
The Difference in Size
• Bacteria can be measured in micrometers
– 0.000001m or 10-6
• Viruses are measured in nanometers
– 0.000000001m or 10-9
The Difference in Definition
• Bacteria: Prokaryotic
Prokaryo Organisms
– Pro: Primitive or “prior to”
– Karyon: Nucleus or “kernel”
– Single-celled organisms
• Viruses: Submicroscopic,
parasitic
Submicroscopic parasitic,
acellular entity composed of a nucleic acid
core surrounded by a protein coat.
– Below the resolution of a microscope
– Relies on a host
– Does not have the properties of cellular life
Bacteria
Two main “domains”
1. Archaea
Cell walls lack peptidoglycan
MadeAdapted
up of types
of peptide
and sugar bonds
to extreme
environments:
•
Extremely hot and cold, salty, without oxygen,
etc.
2. Bacteria
Cell walls with peptidoglycan
Bacteria:
Shapes
• Three basic shapes:
– Rod (Bacilli)
Bacillus anthracis (Anthrax),
Yersinia pestis (Bubonic plague)
• Comma-shaped (Vibrios)
Vibrio cholerae
– Sphere (Cocci)
Streptococcus, Staphylococcus
– Spiral (Spirilla)
Treponema pallidum (Syphillis)
Bacterial Staining
• Gram-positive: Retains the crystals of
violet dye in the peptidoglycan layer
Bacterial Staining
• Gram-negative: Will not pick up the violet dye
Bacterial Growth and Reproduction
• Binary Fission:
Asexual division
• Conjugation:
“Sexual” reproduction
Pilus extends between bacteria
• Spore Formation:
An endospore forms when growth
conditions are unfavorable