Plate 10 The Spectrum of Microorganisms

Cell Size ► The smallest objects visible to the unaided eye are about 0.1 mm long  Amoeba  Human egg  Paramecium

Centimeter ► cm = centimeter ► 1 cm = 1/100 meter ► About the width of your pinky finger

Millimeter ► mm = millimeter ► 1 mm = 1/1000 meter ► About the width of a dime

Micrometer ► μm = micrometer ► Known as a “micron” ► 1 μm = 1/1,000,000 meter microns 6-10 microns Red blood cell Human hair

Nanometer ► nm = nanometer ► 1 nm = 1/1,000,000,000 meter nm 2.5 nm

Dimensional Analysis Convert 33.2 cm into m 1 m 100 cm 33.2 cm x

Dimensional Analysis Convert 33.2 cm into m 1 m 100 cm 33.2 cm x= m

You Try!

Broad Range of Microorganisms ► Can be as small as a virus  50 nm ► Can be as large as Armillaria ostoyae (the “humongous fungus”)  8.9 km 2 (2,200 acres)

“Micro”organisms ► In order for an organism to be a “microorganism”, a microscope must be used to see the details of its structure

Viruses ► Viruses are primarily made from 2 types of molecules:  A protective protein coating (capsid)  DNA or RNA inside

Viruses ► 3 basic virus shapes: Helical IcosahedronComplex

Viruses ► Characteristics of viruses similar to other living organisms:  Can reproduce (only inside other living cells)  Can evolve (mutate)

Viruses ► Diseases caused by viruses:  HIV (AIDS)  Influenza  Chicken pox  Hepatitis  Small pox

Bacteria ► Bacteria are the most abundant organisms in the world, both in number and mass ► Bacteria have the greatest diversity of species ► No one knows for sure how many species there are

Bacteria ► Bacteria can be 100 to 1000 times the size of a virus

Bacteria ► 3 main shapes:  Coccus (spherical)  Bacillus (rod)  Spirochete & spirillum (spiral)

Bacteria

Bacteria ► Roles that bacteria play:  Decomposers – recycle large organic molecules and important elements (C & N)  Relatively few actually cause disease  Help make food and other materials

Cyanobacteria ► Prokaryotic ► Commonly called “blue-green algae”, but they’re more closely related to bacteria than algae ► Original producers of oxygen (O 2 ) on earth  Produce O 2 more than plants!

Cyanobacteria ► In warm, nutrient-rich environments, cyanobacteria can grow very quickly ► Algal blooms can use up oxygen in water, block sunlight, and release toxins

Microscopic Algae ► Two main types:  Dinoflagellates (spinning whips)  Diatoms

Protozoa ► Proto (first), zoa (animals) ► “Animalcules” first seen by Anton von Leeuwenhoek ► Thought to be simplest form of animal and first to appear

Protozoa ► Amoeba – move by pseudopods (“false feet”)

Protozoa ► Flagellates – move by flagella

Protozoa ► Ciliates – move by cilia

Protozoa ► Sporozoa – no locomotion, parasitic

Protozoa ► Diseases caused by protozoa:  Malaria  Sleeping sickness  Giardia  Toxoplasma

Fungi ► Two main types:  Molds – sometimes macroscopic  Yeasts – single-celled

Fungi ► Hyphae – single chain of cells

Fungi ► Mycelium – mass of hyphae

Fungi ► Spore – reproductive structure  Can resist most environmental damage (UV light, temperature extremes, desiccation, etc.)