Transcript Microbiology Review Biology II

Microbiology
Review
Biology II
The Inner Life of the Cell
• See and Hear Video
showing modeled
behavior of cellular life…
Microbiology
The study of single celled
organisms smaller than 1mm in
size with most being too small
to be seen with the naked eye.
History of Human Knowledge
•Used in foods for thousands of
years
•First described 1684 by
van Leeuwenhoek
•Germ Theory of Disease developed
by Koch in the late 1800’s
What Makes a Cell?
• Smallest entity capable of independent
life.
• Separated from the environment by a cell
envelope.
• Always a cell membrane.
• Sometimes includes a cell wall (in plants).
• Contain internal structures.
Who are These Guys?
• Algae
• Protozoa
• Fungi
• Archeabacteria
• Viruses
• Prions and Viroids
• Bacteria
Algae
• Eukaryotes that may be unicellular,
colonial or filamentous.
Algae
• Aquatic or terrestrial.
• Mostly plant-like characteristics.
• Photosynthetic.
• Great variety of types, but all contain
chlorophyll.
• Some animal-like characteristics like
phagocitosis of other organisms.
Algae
Algae
Netrium (algae)
Cladophora Algae
Protozoa
• Single celled eukaryotes, but may form
colonial aggregates.
• Aquatic with animal-like
characteristics.
Paramecium
Amoeba
Protozoa
• Ingest organic matter for nutrients.
• Vary greatly in size from 0.003mm to
5mm.
• Many are human parasites.
• Most are motile.
ozoan Feeding
key innovation: phagocytosis
Raptorial
Feeding: direct
interception of
prey
Volvox
Paramecium
Stentor
Amoeba
Vorticella
Colony
Fungi
• Very diverse group of eukaryotes.
• Not all are microbes (mushrooms).
• Yeasts are unicellular and spherical.
• Molds are filamentous with branching.
Fungi
•Non-photosynthetic.
•Require the uptake of organic
matter for nutrients.
•Saprophytic (feeds on dead matter)
or parasitic (infects the living).
•Propagate by spores.
Archeabacteria
• Single celled prokaryotes.
• Extremophiles.
• 4 broad groups.
•Halophiles (like salty
environments)
•Methanogens (like
swampy environments)
•Sulfur dependent
•Thermophiles (like it
very hot)
Archeabacteria
Viruses
• Consist of nucleic acid and protein.
Viruses
• Obligate intracellular parasites (can
only live within other cells)
• Are they really alive?
• In general, are smaller than most
prokaryotes.
Prions and Viroids
• Prions are proteins that cause diseases like
BSE (Bovine Spongiform Encephalopathy, commonly
known as 'mad cow disease').
• Viroids are small RNA’s with no associated
protein that causes diseases in plants.
• Neither fit the criteria for living organisms,
but they are microbes and are therefore
studied by microbiologists.
Bacteria
• Ubiquitous (they’re everywhere!)
Bacteria
• Reproduce asexually by fission or
sexually by conjugation.
• Vary greatly in shapes, sizes,
metabolisms, and growth conditions.
• Some main characteristics used in
identification are colony appearance
and cell size, shape, physiology and
metabolism.