Class notes
Notes for microbio
- Course
- BIOL 3400
- Institution
- Nova Southeastern University
Notes for microbiology
[Show more]
Seller
Follow
Content preview
MicrobiologyCHAPTER 1: The Microbial World and You
Microorganisms: organisms that are too small to be seen with the unaided eye
- Germ refers to a rapidly growing cell
Microbes in our lives
A few are pathogenic (disease-causing)
- Decompose organic waste
- Are producers in the ecosystem by photosynthesis
- Produce industrial chemicals such as ethanol and acetone
- Produce fermented foods such as vinegar, cheese, and bread
- Produce products used in manufacturing (e.g., cellulase) and treatment
(e.g., insulin)
Knowledge of microorganisms
- Allows humans to
o Prevent food spoilage
o Prevent disease occurrence
- Led to aseptic techniques to prevent contamination in medicine and in
microbiology labs
Naming and Classifying Microorganisms
- Linnaeus established the system of scientific nomenclature
- Each organism has two names: the genus and specific epithet
Scientific Names
- Are italicized or underlined. The genus is capitalized, specific epithet is
lowercase.
- Are “Latinized”
- May be descriptive or honor a scientist
Staphylococcus aureus-
- Describes the clustered (staphylo-) spherical (cocci) cells
- Describes the gold-colored (aureus) colonies
,Escherichia coli-
- Honors the discoverer, Theodore Escherich
- Describes the bacterium’s habitat (large intestine, or colon)
Types of Microorganisms
- Bacteria
o Prokaryotes
o Peptidoglycan cell walls
o Binary fission
o For energy, use organic chemicals, inorganic chemicals, or
photosynthesis
- Archaea
o Prokaryotic
o Lack peptidoglycan
o Live in extreme environments
o Include
▪ Methanogens
▪ Extreme halophiles
▪ Extreme thermophiles
- Fungi
o Eukaryotes
o Chitin cell walls
o Use organic chemicals for energy
o Molds and mushrooms are multicellular, consisting of masses of
mycelia, which are composed of filaments called hyphae
o Yeasts are unicellular
- Protozoa
o Eukaryotes
o Absorb or ingest organic chemicals
o May be motile via pseudopods, cilia, or flagella
- Algae
o Eukaryotes
o Cellulose cell walls
o Use photosynthesis for energy
o Produce molecular oxygen and organic compounds
, - Viruses
o Acellular
o Consist of DNA or RNA core
o Core is surrounded by a protein coat
o Coat may be enclosed in a lipid envelope
o Viruses are replicated only when they’re in a living host cell
- Multicellular animal parasites
o Eukaryotes
o Multicellular animals
o Parasitic flatworms and roundworms, helminths
o Microscopic stages in life cycles
Three domains-
- Bacteria
- Archaea
- Eukarya
o Protists
o Fungi
o Plants
o Animals
Cell theory: All living things are composed of cells and come from preexisting
cells (Virchow).
- 1673-1723: Anton van Leeuwenhoek described live microorganisms
The First Observations
- Robert Hooke observed that cork was composed of “little boxes”; he
introduced the term cell (1665).
- Hooke’s observations laid the groundwork for development of the cell
theory, the concept that all living things are composed of cells.
- Anton van Leeuwenhoek, using a simple microscope, was the first to
observe microorganisms (1673).
Spontaneous generation: The hypothesis that living organisms arise from
nonliving matter, a “vital force” forms life
Biogenesis: the hypothesis that living organisms arise from preexisting life
, The Debate over Spontaneous Generation
- Until the mid-1880s, many people believed in spontaneous generation, the
idea that living organisms could arise from nonliving matter.
- Francesco Redi demonstrated that maggots appear on decaying meat
only when flies are able to lay eggs on the meat (1668).
- John Needham claimed that microorganisms could arise spontaneously
from heated nutrient broth (1745).
- Lazzaro Spallanzani repeated Needham’s experiments and suggested
that Needham’s results were due to microorganisms in the air entering his
broth (1765).
- Rudolf Virchow introduced the concept of biogenesis: living cells can
arise only from preexisting cells (1858).
- Louis Pasteur demonstrated that microorganisms are in the air
everywhere and offered proof of biogenesis (1861).
- Pasteur’s discoveries led to the development of aseptic techniques used
in laboratories and medical procedures to prevent contamination by
microorganisms.
o Proved biogenesis (S-shaped flask)
The Golden Age of Microbiology
- 1857-1914
- Beginning with Pasteur’s work, discoveries include the relationship
between microbes and disease, immunity, and antimicrobial drugs.
Fermentation and Pasteurization-
- Pasteur found that yeast ferment sugars to alcohol and that bacteria can
oxidize the alcohol to acetic acid.
- Fermentation: the conversion of sugar to alcohol to make beer and wine
- A heating process called pasteurization is used to kill bacteria in some
alcoholic beverages and milk. (High heat, short time)
The Germ Theory of Disease
- Agostino Bassi (1835) and Pasteur (1865) showed a causal relationship
between microorganisms and disease.
The benefits of buying summaries with Stuvia:
Guaranteed quality through customer reviews
Stuvia customers have reviewed more than 700,000 summaries. This how you know that you are buying the best documents.
Quick and easy check-out
You can quickly pay through credit card or Stuvia-credit for the summaries. There is no membership needed.
Focus on what matters
Your fellow students write the study notes themselves, which is why the documents are always reliable and up-to-date. This ensures you quickly get to the core!
Frequently asked questions
What do I get when I buy this document?
You get a PDF, available immediately after your purchase. The purchased document is accessible anytime, anywhere and indefinitely through your profile.
Satisfaction guarantee: how does it work?
Our satisfaction guarantee ensures that you always find a study document that suits you well. You fill out a form, and our customer service team takes care of the rest.
Who am I buying these notes from?
Stuvia is a marketplace, so you are not buying this document from us, but from seller j1377. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy these notes for $4.49. You're not tied to anything after your purchase.
Can Stuvia be trusted?
4.6 stars on Google & Trustpilot (+1000 reviews)
67447 documents were sold in the last 30 days
Founded in 2010, the go-to place to buy study notes for 14 years now