Microbio notes Essay

Submitted By ejchoi
Words: 6946
Pages: 28

Branches of Microbiology: Bacteriology, Parasitology, Protozoology, Phycology (algae), Mycology, Immunology
Distinguishes between 6 types of microorganisms:
-Lack cell wall
-Classified by motion type (flagella, pseudopod, cilia)
-No movement in adult form
-Help digest cellulose
-Few are pathogenic
-Chitin in cell wall
-Decompose organic matter
-Yeasts (unicellular) & molds (hyphae)
-Affects 1/5 of world’s population
-Unicellular OR multicellular
-Simple reproductive structures
-Categorized by pigmentation, storage products, & cell wall composition
-Neither prokaryotic/eukaryotic
-Needs living host to -replicate

-Most contain (PPG) in cell wall
-Very diverse
-NOT pathogenic
*Archaea in own domain Domains: Prokaryotes -Eubacteriaq -Archaea Eukaryotes -Eukarya -Multicellular organisms (fungi, plants, animals

Rules for taxonomy in naming a species Created by Carolus Linnaeus Bacterial taxonomy – Bergey’s Manual of Systematic Bacteriology Genus + species (binomial nomenclature) Ranks below species = subspecies Rank above kingdom = domain

3 features of Archaea + 3 types: -NO PPG Methanogens – generate CH4 -Strange lipids in membrane Halophiles – salt-loving -Unique rRNA Thermophiles – heat-loving (extremophiles)

Discoveries Anton van Leeuwenhoek
Discovered microbial world
1st microscope
Saw “animalcules”
Louis Pasteur
Yeast responsible for fermentation
Formulated (but never proved) the Germ Theory of Disease
Robert Koch
Staining techniques
1st photomicrograph of bacteria
Aseptic techniques
Steam as sterilizer
Invented use of Petri dish
Proved Germ Theory of Disease
Florence Nightingale
Sterile techniques in surgical settings (military)
John Snow
Infection control & epidemiology
Cholera outbreak in London
Joseph Lister
Antiseptic techniques
Ignaz Semmelweiz
Perpetual Fever caused deaths of mothers
Death rates increased in ward w/ med students (using cadavers & not washing hands in b/t patients)
Germ Theory of Disease
Formulated by Pasteur, proved by Koch
*The theory that many disease are caused by the presence and actions of microorganisms in the body
Proved by Koch’s postulates
Bacillus anthracis caused anthrax
Same microorganisms are present in every case of the diseases
Microorganisms isolated from tissues of a dead animal (sheep), and a pure culture is prepared
Microorganisms from pure culture are inoculated into a healthy animal (mouse). The disease is reproduced.
The identical microorganisms are isolated & recultivated form the tissue specimens of the experimental animal
Cell Structure & Function
Why Compartmentalization is a key distinction b/t eukaryotes and prokaryotes:

Cell Structure
Chromosomes: single DNA molecule in a circular loop
Metabolism: w/in cytoplasm
Ribosomes: 70s (30s + 50s), free-floating
Cell wall: most bacteria have PPG in cell wall
Chlorophyll: dissolved in membranes
Cell membrane (PM): proteins & lipids; in constant flux; lipid bilayer w/ proteins (Fluid Mosaic Model)

Chromosomes: multiple chromosomes, proteins (histones) associated w/ DNA
Metabolism: w/in cristae (mitochondria)
Ribosomes: 80s; primarily bound to ER
Cell wall: algae (cellulose); fungi (chitin); animals lack cell walls
Chlorophyll: contained in chloroplasts
Cell membrane (PM): proteins & lipids; in constant flux; lipid bilayer w/ proteins (Fluid Mosaic Model)

Bacterial Shapes Bacilli (rods) - ~0.5-2.0 micrometers - Some species are spore-forming (Clostridium, Bacillus) - Streptobacilli = chain Cocci (sphere)
Diplococci: pair after reproduction (N. gonorrhaea)
Sarcina: cube of 8 cocci (Micrococus luteus)
Streptococci: chain of