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Micro chapter 1


the study of living things too small to be seen w/o magnification

microorganisms, microbes

microscopic organisms (commonly called germs, viruses, agents, etc.) but not all cause disease, many more are useful and essential to human life

we would not be here w/o microorganisms. they help recycle

major groups of microorganisms

bacteria, algae, protozoa, helminthes (worms), parasitic invertebrate animals and fungi

Branches of Microbiology (6)

-Agricultural = plant things w/bacteria
-Biotechnology = E. coli producing insulin
-Food, dairy and aquatic
-Genetic engineering & recombinant DNA technology)
-Public health micro and epidemiolgy = CDC, samonella

what are GMOs?

Modified genomes such as strawberries, medical & food

emerging areas of Micro (3)

-Geomicrobiology = microbes in the earth's crust
-Marine = why was it limited before? how do you mimic these things w/in the lab
-Astromicrobiology = potential microbial life in space

Impact of Microbes on Earth:
small organisms w/a giant effect

1. microorganisms have profound influence on all aspects of the earth and its residents
2. bacterial-like organism in fossil records 3.5 billion years ago (prokaryote organisms w/o true nucleus
3. 2 billion years later, eukaryotes (nucleus)
4. Karyote = seed = all items needed to recreate

Ubiquity of Microorganisms

1. found nearly everywhere
2. occur in large numbers
3. live in places many other organisms can't

Microbial involvement in energy & nutrient flow

1. bacteria conducted photosynthesis before plants appeared. Autotroph
a. anoygenic photosynthesis = w/o O2, usually O2 is toxic to them
b. oxygenic photosynthesis
2. biological decomposition and nutrient recycling
3. Typical cycles = Carbon & Nitrogen. DNA---proteins---nitrogen

human use of microorganisms

been using them for thousands of years

Ex. bakers and brewers yeast, cheeses (fungi & bacteria can make), moldy bread on wounds (precursor to penicillin), meat tenderization (hypae of fungi break down bonds btw cells), creation of acids and acetone, pickling/preserving food, cleaning of oil spills


When humans manipulate microorganisms to make products in an industrial setting

1. genetic engineering = create new products and genetically modified organisms (GMOs)

2. Recombinant DNA technology = allow microbes to be engineered to synthesize desirable proteins (drugs-insulin, hormones-growth, and enzymes). 2 different organisms need to be involved.

recombinant DNA technology
What must an organism require in order to make "desirable proteins"?

new DNA


introducing microbes into the environment to restore stability or clean up toxic pollutants.

Oil and chemical spills = need to ingest & then breakdown
water and sewage treatment

worldwide infectious diseases

1. increasing # of emerging diseases (SARS, AIDS, hepatitis C, H1N1 MRSA, VRE)
2. other diseases previously not linked to microorganisms now are (gastric ulcers, certain cancers, schizo, MS, OCD coronary artery disease)
3. increasing # of drug resistant strains


disease causing organisms


cold loving


cold tolerant


middle temp loving


heat loving. not pathogenic


really hot loving. not pathogenic

General characteristic of Microorganisms

1. Cellular organization
a. Prokaryotic vs. eukaryotic cells
i. prokaryotic cell are 10 times smaller than eukaryotic cells because = no organelles, no compartments. only function is to get food & reproduce
ii. prokaryotic cells lack many cell structures such as organelles. organelles are tiny organs of cells w/their own function.
iii. all prokaryotes are microorganism, but only some eukaryotes are.

organelles - what are they & give example

small double membrane-bound structures

ex. mitochondria, chloroplast


1. not independently living cellular organisms
2. much simpler than cells. basically a small amount of DNA or RNA wrapped in protein and sometimes by lipid membrane
3. individuals are called a virus particle or virion
4. depend on the infected cell's machinery to multiply and disperse
viruses = noncellular, parasitic protein-coated genetic elements that can infect all living things, including other microorganism

Viruses do not have components of a cell and are non-living.

virus particle or virion

an individual virus

Lifestyles of microorganisms

1. most live free existence (in soil or water, for example

2. some are parasitic and live in hosts

Historical foundation of microorganisms

1. key to the study of microorganisms was the development of the microscope

2. earliest record of microbes was from the work of Robert Hooke in 1660s who termed "cell"
3. most careful observation was possible after Antonie van Leeuwenhoek created single-lense microscope
a. aka - father of bacteriology & protozoology
b. he was in textiles to determine quality

Establishment of Scientific Method

1. early scientists = mixture of belief, superstition & argument
2. during 1600s true scientific thinking developed
3. development of scientific method
a. formulate hypothesis
b. most use deductive approach (experiments & testing) to apply scientific method
c. experimentation, analysis, and testing leads to conclusion
4. hypothesis can eventually become theories. ex. evolution, endosymbiotic
5. theories can eventually become laws or principles. Ex. biogenesis, gravity, thermodynamics


tentative explanation for what has been observed or measures


collection of statements, propositions concepts to explain an event

Pattern of deductive reasoning #1
(well established principle)

1. hypothesis
2. predictions
3. testing
4. theory/principle

Pattern of deductive reasoning #2
(new hypothesis in early stages)

1. hypothesis
a. modify or possible discard
2. predictions
3. testing/results
a. modify or possibly discard
4. theory

Development of Medical microbiology
Discovery of Spores & Sterilization

a. Louis Pasteur - 1st worked w/ infusions, 1800s
b. John Tyndall - evidence that some microbes have very high heat resistance & difficult to destroy
c. Ferdinand Cohn - discovered that there are some resistant spores (typically outside) & sterilization

Development of Medical microbiology
Development of Aseptic Techniques

1. physician & scientists suspect microorganisms could cause disease
2. Joseph Lister - introduced aspectic technique prior to surgery.


free of all life forms & virus particles

What were Listers aspetic introductions?

disinfecting hands & air w/antiseptic chemicals (phenol)

Discovery of pathogens & Germ Theory of Disease

1. Louis Pasteur
a. Pasteurization = heating up enough to kill bacteria
b. Germ Theory of Disease = human disease arising from infection (from microorganisms)

2. Robert Koch
a. Koch's postulates verified Germ Theory=could establish whether an organism was pathogenic and which disease it caused = by finding the illness, then isolate the bacterium & give to something else (cows) & see if next cow gets sick
b. discovered Bacillus anthracis (bacillus = spores found in soil or animal hides) caused anthrax
c. major role in the study of microorganisms by culturing & growing microbes

Germ Theory of Disease

human disease arising from infection (from microorganisms)


heating up enough to kill bacteria

Koch's postulates

series of proofs verifying germ theory & whether organisms are pathogenic (ability to cause disease) & which disease it caused.

find the illness, then isolate the bacterium & give to something else (ex. cows) & see if cow get sick

Biogenesis vs. spontaneous generation

Redi experiment = closed meat equals no maggots
open meat equal flies hatching into maggots

Schultze & Schwann test = air inlet, flame heats air, previously sterilized infusion remains sterile

Pasteur's test = microbes destroyed with heat, broth free of live cells (sterile), no air (neck of tube intact) gets to broth = sterile, air get into broth (neck of tube broken) = growth appears

Taxonomy definition

science of classifying living being & identifying organisms

Taxonomy (4)

1. problem w/common names - vary w/ regions
2. microbial nomenclature - naming microorganisms
3. identification - discovering and recording the traits of organisms so they can be named and classified
4. levels of classification - divide from most broad to most specific

microbial nomenclature

naming microorganisms

dumb king philip came over for green spaghetti

domain, kingdom, phylum, class, order, family, genus, species

Assigning specific names

standard nomenclature allows scientists to talk all over world

Binomial system of nomenclature

1. binomial = two-name
2. the generic (genus) name followed by the species name
3. Generic is capitalizeed, species is lowercase ****
4. both are italicized or underlined if italics aren't available ****
5. Staphylococcus aureus = clusters of berries that are gold

Scientific names

1. latinized and used worldwide
2. may be descriptive or honor a scientist

Origin & Evolution of Microorganisms
Phylogeny & evolution

A. Phylogeny = degree of relatedness btw groups of living beings
B. based on process of evolution = hereditary info in living things change gradually thru time, results in structural & functional changes thru generations. adapt thru genetic mutation
Two preconceptions
1. all new species originate from preexisting species (biogenesis)
2. closed related organisms have similar features b/c evolved from common ancestor
C. phylogeny usually represented by a tree showing the divergent nature of evolution


degree of relatedness btw groups of living beings


differing from each other or a standard

difference btw prokaryote & eukaryote

no nucleus vs. nucleus

prokaryote - 2 domains

based on cell analysis (morphology & physiology) and genetic comparisons it was determined that prokaryote have 2 domains

Bacteria & Archaea

4 Kingdoms of Eukaryote

1. Plants
2. Protista
3. Animal
4. Fungi

What prokaryotic kingdom humans most related?


Explain important contributions microorgansims make in earth's ecosystems

flow of enery & food.
production of oxygen
decomposition & nutrient recycling

describe in detail 5 different ways in which humans exploit microorganism for our benefit

breakdown of oil spills
vaccines/insulin- manufacture drugs
mine precious metals
yeast/ferment fruit
plant producing natural pesticides

differentiate btw taxonomy, classification & nomenclature

taxonomy = classifies living beings & identifying organisms
nomenclature = system of naming
classification = dividing from most broad to most specific, arranges organisms into a hierachy w/in taxonomy


belief that living things can only arise from other of the same kind

spontaneous generation

early belief that living things arose fromvital forces present in nonliving or decomposing matter


complete set of chromosomes & genes in an organism

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