Microbes (Prokaryotes!)

Laboratory 8Biology 101

Three domains of life: two are prokaryotic

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?

Types of microbial metabolism

Sickness: bacterial or viral?

Often similar symptoms with different pathwaysViruses are FAR more common

Antibiotic Resistance – take all of your antibiotics, or else….

So what is a virus? (hint: It’s NOT a bacteria)- non-living- very small - uses lipids and proteins taken from host

Ebola Virus – named after the Ebola River

Today in lab:

Bacterial Shapes

Colony Shape

Colony Color