microbes (prokaryotes!) laboratory 8 biology 101
TRANSCRIPT
ProkaryotesAn organism that lacks a membrane-enclosed nucleus
and other membrane-enclosed organelles
ProkaryotesAn organism that lacks a membrane-enclosed nucleus
and other membrane-enclosed organelles
Bacteria
• Unicellular microorganisms• a few micrometers in length• Numbers…• 40 million bacterial cells in a gram of soil• 1 million in a milliliter of freshwater• Approximately 10x as many bacterial cells as human cells in the
human body – most on skin & digestive tract• Approximately 5 nontrillion (5 x 1030) on earth!
5,000,000,000,000,000,000,000,000,000,000
Where are bacteria found?
• EVERYWHERE!• In the soil and water• On and in our bodies• In the air we breathe
• Critical to nutrient cycling as decomposers• Some cause disease• Vast majority are harmless, but half of all human diseases
are caused by bacteria
Anatomy of a Bacterium• Some examples of
differences between bacteria and eukaryotic cells?• Cell wall• Capsule• Ribosomes
• How could these differences help fight disease?
Sickness: bacterial or viral?
Often similar symptoms with different pathwaysViruses are FAR more common
So what is a virus? (hint: It’s NOT a bacteria)- non-living- very small - uses lipids and proteins taken from host