Microbiology Unit One

Chapters 1-7

What is a Microbe?

Microbes are mainly living organisms, but not always.

• for the most part, too small to be seem with the unaided eye, not always

  • Examples include Bacteria, Fungi, Protozoa, Microscopic Algae, and Viruses, as well as Multicellular Animal Parasites.

Pathogenic

disease producing

how to microbes generate oxygen?

via photosynthesis

what kind of chemical products can microbes create?

ethanol, acetone, and vitamins

what kind of fermented foods can microbes create?

vinegar, cheese, and bread

what product can microbes make for manufacturing?

cellulosewhat

what product can microbes make in disease treatment?

insulin

knowledge of microorganisms allows humans to:

• prevent food spoilage

• prevent disease

• understand causes and transmission of disease to prevent epidemics

Carolus Linnaeus

established the system of scientific nomenclature in 1735.

Each organism has two names":

the genus and the specific epithet

How to format Scientific names

• they are either italicized or underlined.

  • the genus is capitalized

  • the specific epithet is lowercase

Bacteria

• Prokaryotes

  • prenucleus

• Single celled

• peptidoglycan cell walls

• Divide via binary fission

• derive nutrition from organic or inorganic chemicals or photosynthesis

• may “swim” by using moving appendages called flagella

  • SEM= 50 micrometers

Archaea

• prokaryotes

• lack peptidoglycan cell walls

  • may lack a cell wall entirely

• often live in extreme environments

• generally not known to cause disease in humans

examples of archaea

• methanogens

• extreme halophiles

• extreme thermophiles

Fungi

• eukaryotes

• chitin cell walls

• absorb organic chemicals for energy

• yeasts are unicellular

  • molds and mushrooms are multicellular

• SEM: 50 micrometers

eukaryotes

distinct nucleus surrounding the DNA (genetic material)

molds consist of

masses of mycelia, which are composed of filaments called hyphae

masses of mycelia are composed of filaments called

hyphae

Protozoa

• eukaryotes

• absorb or ingest organic chemicals

• may be motile via pseudopods, cilia, or flagella

• free-living or parasitic

  • some are photosynthetic

• can reproduce sexually or asexually

• SEM: 50 micrometers

parasitic

derives nutrients from a living host

algae

• eukaryotes

• cellulose cells walls

• found in freshwater, saltwater, and soil

• Uses photosynthesis for energy

  • Produces Oxygen and Carbohydrates

• both sexual and asexual reproduction is possible

• LM: 300 micrometers

Viruses

• acellular

• consist of DNA or RNA core

• core is surrounded by a protein coat

  • coat may be enclosed in a lipid envelope

• are replicated only when they are in the living host cells

  • are inert outside of living hosts

• TEM: 70nm

Multicellular Animal Parasites

• eukaryotes

• multicellular animals

• not strictly microorganisms

• parasitic flatworms and roundworms are called helminths

  • some microscopic stages in their life cycles

Carl Woese

developed the classification of microorganisms in 1978

three domains

bacteria, archaea, eukarya

4 classes of eukarya

protists, fungi, plants, and animals