Chapters 1 & 10 Flashcards
Mycologists study…
microscopic fungi
Microbiology
definition
The study of small (usually microscopic) organisms
Who is the father of microbiology
Antony Van Leeuwenhoek
Antony van Leeuwenhoek
Observed “animalcules” in lake water in 1674
Dutch Drapery Merchant
Made simple magnifying glass
Robert Hooke
1665, England
First to describe and name “cells” found in cork tissue
Described “microscopical mushroom” (common bread mold)
Scientists responsible for cell theory and year
1800s
Schleiden (Botanist)
Schwann (Human Anatomist)
Cell Theory
- All organisms consist of one or more cells
- Cells are the basic organizational unit of all living things
- All living cells arise from other pre-existing living cells (biogenesis)
Theories on where microorganisms come from
Spontaneous generation
Biogenesis
Spontaneous Generation
Life arises spontaneously from non-living material
Biogenesis
All living cells arise from other pre-existing living cells
Who helped disprove Spontaneous Generation and years
Francesco Redi - 1668
Needham and Spallanzani - 1749, 1776
Louis Pasteur - 1861
Francesco Redi
Disproved spontaneous generation in 1668 by studying maggots and rotting meat
Needham and Spallanzani
Priests that studied boiling broths in 1749 and 1776
Needham corked broth and still ended up with bacteria in both broths r/t possible contamination
Spallanzani melted the top on one of the flasks and it grew no bacteria
Louis Pasteur
1861
filtered air and swan-necked flasks
bacteria would form in the neck of the flask but not in the broth unless tipped sideways
Pasteur’s Experiments
- No living things arise by spontaneous generation
- microbes are everywhere
- growth of microbes causes dead tissue to decompose and food to spoil - Pasteurization
Pasteurization came through studying…
wine spoilage
Three people responsible for theory of heat resistant microorganisms and in what year?
1876
John Tyndall
Ferdinand Cohn
Robert Koch
John Tyndalls theory against spontaneous generation
heat-resistant microorganisms
Ferdinand Cohn theory against spontaneous generation
endospores
Endospores
seed like hard exterior that is able to withstand heat
Robert Koch’s theory against spontaneous generation
anthrax spores
Difference between negative control and positive control
Negative control - nothing should happen
Positive control - reactions happen as planned
Science
organized body of knowledge about natural world
Scientific method
steps used to gain information about natural world
- observation
- hypothesis
- experiment
- conclusion
2 major types of bacteria that for endospores
Bacillus and Clostridium
Progression of Scientific ideas
- Peer review/publication
- further experimentation
- theory
- scientific law
Germ Theory
Late 1800s
Microbes cause disease and specific microbes cause specific diseases
Ignaz Semmelweis
1841
believed that childbirth infections spread by doctors in hospitals
Joseph Lister
1865
clean wounds and antiseptic surgery
phenol/carbolic acid
Robert Koch
late 1800s
Proved germ theory studying Anthrax (Bacillus anthracis)
Koch’s postulates
- the suspect agent must be present in every case of the disease
- The suspect agent must be grown in pure culture from diseased hosts
- The same disease must be produced when a pure culture of the agent is given to a healthy, experimental host
- The same agent must be recovered from the experimentally infected host`
4 importances of microbiology
- Necessary for human life and other forms of life
- Economic Applications
- Scientific research
- Medical Microbiology
Why is microbiology necessary for human life and other forms of life
- Oxygen gas production
- Nitrogen Fixation - convert N2 gas to a usable form
- Decomposition - cellulose, dead material and waste *only bacteria can break down cellulose
Why microbiology is important of Economic Applications
- Food Production (bacteria and yeast fermentation)
- Biotechnology (Drug production & health of agriculture)
- Bioremediation (decomposers speed up decay of pollutants, clean up of oil, DDT spills)
Why is microbiology important for scientific research?
Easy to study - grow quickly, inexpensive
Similar to more complex larger animals
“what is true of elephants is true of bacteria”
Why is microbiology important for Medical Microbiology
- Over 1/2 the worlds pospulation has died of malaria
- 20 million dies each year from preventable diseases
- In US 750 million infection diseases each year - over 200,000 fatal
What are the top two infectious disease killers in the world
Diarrhea and Pneumonia
Controlling Infection Diseases
- Improving sewage disposal - Chadwick
- Assuring clean public water supply
- Food preservation and inspection - Pasteurization
- Improving personal hygiene
- Developing antiseptic techniques - Lister
3 further methods of controlling infection disease
Chemotherapy
Antibiotics
Vaccines
Chemotherapy
Use of chemical to treat a disease
- cleaning inanimate objects and human tissue
- medications
Antibiotics
antibacterial compounds produced by fungi and bacteria
Vaccines
preparation of a pathogen or its products to provide immunity
Bacteria are very diverse in…
Phenotype (physical characteristics)
Genotype (genes, RNA, DNA)
Ecological characteristics
Phenotype
Physical characteristics
Morphology
size and shape
Genotype
Genes, RNA and DNA
Ecology
relationship with environment and other organisms
types of Ecology
Free-living
Symbiotic
Free-living
Organism that is not directly dependent on another organism for survival.
Groupings based on energy and source of organic molecules (autotrophs and heterotrophs)
Autotrophs
“self feeding”
free-living
source of carbon is CO2
Source of cellular energy = inorganic molecules for chemoautotrophs or photons for photoautrophs
Examples of Photoautotrophs
Cyanobacteria - use photosynthesis
Purple Bacteria - anaerobic, use H2S and produce S2
Why are purple bacteria purple
to gather light for photosynthesis
Overall equation for photosynthesis
CO2 + H20 + light = C6H12O6 + O2
Examples of Chemoautotrophs
Methanogens (anaerobic) - H2 gas + CO2 -> CH4 (methane) + H20
Sulfer-oxidizing - H2S +O2 -> H2SO4
Two types of autotrophs
Chemoautotrophs and Photoautotrophs
Two types of free-living microorganisms
Autotrophs (self-feeding)
Heterotrophs (other feeding)
Heterotrophs
“Other feeding”
Ex. humans and animals, some bacteria
Source of carbon: organic molecules from other organisms
Source of cellular energy: organic molecules from other organisms
Consume or absorb nutrients
subset of Heterotrophs that only feed on dead organisms
Decomposers
Decomposers
organisms that use simple organic molecules from dead organisms
cellular energy and source of carbon both come from dead organisms
Symbiotic microorganisms
organisms that live on or in another organism and depend on that organism for survival.
Symbiont is the smaller organism and the larger is the host
Types of symbiosis
Mutualism
Commensalism
Parasitism
Mutualism
both the symbiont and the host benefit
Example:
Rhizobia - live in nodules in pant roots, nitrogen fixation
Lactobacillus spp. - produces and acidic environment in the vagina that inhibits bacterial growth.
Commensalism
The symbiont benefits but the host is neither harmed nor helped
Example: skin microbiota
Parasitism
The symbiont benefits, but the host is harmed
Two types of parasites
Exotic
Opportunistic (endemic)
Exotic parasites
pathogen not typically found in the human body, can invade and cause harm
ex. cold and flu viruses
Opportunistic (endemic) parasites
normal microbiota can inflict harm when the host immunity is weakened
ex. strep pneumonia
Taxonomy
Study of organisms in order to arrange them into groups (taxa)
3 parts of taxonomy
Classification
Identification
Nomenclature
Classification
the orderly arrangement of organisms into groups that have similar characteristics
Nomenclature
naming
Who created the scientific naming of organisms
Carolus Linnaeus in 1753
called it binomial nomenclature
Binomial nomenclature
Two latin words
Genus name is capitalized, species name is not
Italicized or underlined
Names are descriptive and/or honorary
Trick to remember Classification system order
Do Keep Piling Chocolate On For Goodness Sake
Classification order
Domain Kingdom Phylum Class Order Family Genus Species
Bacterias order normally ends in
-ales
Bacteria’s family often ends in
-aceae
How many kingdoms are there?
5 Monera/Prokarya Protista Fungi Plantae Animalia
How are organisms classified into kingdoms?
- number of cells
- cell type
- nutrition and energy requirements
- cell wall composition
Kingdom Monera/Prokarya
Unicellular
Prokaryotic
Chemoautotroph, photoautotroph, heterotroph (decomposers and all types symbiosis)
True bacteria have peptidoglycan in the cell wall
True bacteria have what in the cell wall
peptidoglycan
Examples of Kingdom Monera/Prokarya
Bacteria, Cyanobacteria, Archaeabacteria
Kingdom Protista
Mostly unicellular Eukaryotic Photoautotroph and/or heterotroph Algae, water molds - cell walls with cellulose in some protozoa - no cell wall
Examples of Kingdom Protista
Algae (Euglena, diatoms)
Protozoa (Amoeba, Paramecium)
Water molds
Kingdom Fungi
Mostly multicellular
Eukaryotic
Heterotrophs by absorption (mostly decomposers, also symbiotic, including parasites)
Cell walls of chitin
Examples of Kingdom Fungi
Yeast
Mold
Mushrooms
Kingdom Plantae
Multicellular
Eukaryotic
Photoautotrophs
Cell walls of cellulose
Examples of Kingdom Plantae
Mosses, ferns, conifers, flowering plants
NO MICROORGANISMS in plant kingdom
Kingdom Animalia
Multicellular
Eukaryotic
Heterotrophs by consumption
NO CELL WALLS
Examples of Kingdom Animalia
Coral, sponges, insects, worms, reptiles, birds, mammals
parasitic helminth worms are the ONLY microorganisms in the animal kingdom.
Phylogeny
using evolutionary relationships to classify organisms
- difficulties with microorganisms because of strains, mutations, asexual reproduction
- molecular techniques (ex. DNA sequencing) helpful in constructing phylogenetic trees
Phylogenetic Tree 3 main groups
Bacteria
Archaea
Eucarya
Three Domains
Bacteria
Archaea
Eucarya (kingdoms Protista, Fungi, Plantae, Animalia)
Who decided that prokaryotes should be split into two domains?
Carl Woese - University of Illinois in the later 1970s
3 movements of Protistas
Flagella
Cilia
Psudopodia
Domain Bacteria
- same characteristics as Bacteria kingdom (prokaryotes with peptidoglycan in cell walls)
- Most have specific shapes
- Reproduce asexually with BINARY FISSION
- Many move using flagella
Domain Archaea
- Similar to Bacteria Domain
- Cell walls vary greatly and do not have peptidoglycan
- can survive in extreme conditions
- rRNA different from bacteria and eucarya
- show differences in cell membrane, ribosomes, DNA(histones) and tRNA
- not known to cause any human diseases
Domain Eucarya
Eukaryotes
Kingdoms protista, fungi, plantae, animalia
microbial members include fungi, protists, larvae stages of helminths
Infectious agents
Agent capable of causing an infection
Capable of self-replication
Free-living infection agents - require host for nutrition but not reproduction
Examples of infectious agents
Bacteria, fungi, protists, helminths
Acellular infectious agents
virus, viroid, prion
Acellular: not classified with domain or kingdom systems
Non-living
Can infect all forms of life
Viruses
Nucleic acid (DNA or RNA)
Protective protein layer (capsid)
1/10 to 1/1000 size of bacteria
nonmotile
Study of viruses
Virology
Viroids
small piece of RNA without protein coat
much smaller than viruses
cause plant diseases
unknown if infect animals
Prions
Small piece of protein only, no nucleic acid
- Abnormal shape
- “self-replicating”
- Affect brain and nerve tissue, fatal and untreatable
Ex. “mad cow disease”bovine spongiform encephalopathy
Creutzfeldt-Jakob disease
Size of most bacteria
1 - 10 micrometers
size of most viruses
20 - 100 nanometers
0.20 -0.1 micro meters
