Term
|
Definition
| It was discovered that some microbes in the dust and air were resistant to high heat, spores being the most resistant, which led to the word sterile meaning "completely free of all life forms" |
|
|
Term
|
Definition
| Early belief that some forms of life could arise from vital forces present in nonliving or decomposing matter. |
|
|
Term
|
Definition
| He was on the first people to test the Spontaneous Generation theory |
|
|
Term
|
Definition
| Sought to prove that the air was the source of microbes and tried by passing air through strong chemicals or hot glass tubes into heat treated infusions in glass |
|
|
Term
|
Definition
| Entered the swan-neck flask experiment and showed microbes caused fermentation and spoilage and disproved Spontaneous Generation. Developed Pasteurization (56 degrees Celsius in the absence of oxygen) |
|
|
Term
|
Definition
| Ignas Semmelweis and Joseph Lister introduced Aseptic technique in order to reduce microbes in a medical setting and prevent wound infections |
|
|
Term
|
Definition
| Many diseases are caused by the growth of microbes in the body and not by sins, bad character, poverty, etc. Microorganisms can invade macro organisms and cause disease. |
|
|
Term
| 4 parts of Koch's postulates |
|
Definition
1. Specific causative agent must be found in every case
2. Infectious agent must be isolated in pure culture
3. Inoculation of pure infectious agent into susceptible animal must result in same disease.
4. Infectious agent must be recovered from inoculated animal |
|
|
Term
| Why can't Koch's postulates be applied to all infectious agents? |
|
Definition
Antibodies- if your body gets rid of it, it would be hard to recover.
A lot of agents can not be cultured
You have to have a susceptible host. Some animals are immune to some diseases
Multiple organisms working together to cause disease. |
|
|
Term
| What is the community theory of disease? |
|
Definition
In natural environment, microorganisms live as multi-species communities
In the hospital over 80% of infections arise from polymicrobial communities |
|
|
Term
|
Definition
| forms of life that are smaller than the human eye can detect without aids |
|
|
Term
|
Definition
| The science of classifying living things. Developed by Linnaeus. Primarily concerned with classification, nomenclature, and identification. |
|
|
Term
|
Definition
| In the levels of classification, the broadest general category to which an organism is assigned. Members of a domain share only one or a few general characteristics. |
|
|
Term
|
Definition
| term used for nonarchaea prokaryotes, means "true bacteria". |
|
|
Term
|
Definition
| Prokaryotic single-celled organisms of primitive origin that have unusual anatomy, physiology, and genetics and live in harsh habitats, |
|
|
Term
|
Definition
Binomial (scientific) nomenclature
Genes- Bacillus always capitalized
Species- subtilis lowercase
either italicized or underlined
Bacillus subtilis (B. subtilis) |
|
|
Term
|
Definition
| One of the three domains of living organisms, as proposed by Woese; contains all eukaryotic organisms. |
|
|
Term
|
Definition
| discovered cells could ingest microbes "phagocytes" |
|
|
Term
|
Definition
| discovered certain dyes. Specifically bacteria staining. |
|
|
Term
|
Definition
| discovered lysozyme in 1922 and developed penecilin. |
|
|
Term
|
Definition
Chamberland (1840)- developed porcelain filters to remove bacteria from water.
Beijernick- Discovered some agents were not removed.
Wendell Stanley (1935)- Crystallized by electron microscope (1939)
Hershey and Chase (1952)- Demonstrated that DNA could be transferred from generation to generation. |
|
|
Term
|
Definition
| Discovered certain dyes specifically stained bacteria. |
|
|
Term
|
Definition
| Discovered lysosome in 1922 and developed penicillin. |
|
|
Term
|
Definition
| His discoveries spawned a new field of genetics. His work was ignored for ~30 years and then exploded. |
|
|
Term
|
Definition
| Discovered diplococcus (Streptococcus pneumoniae) could change from non-pathogenic to pathogenic |
|
|
Term
| Avery, McCarty and Macleod |
|
Definition
| Furthered Griffin's work-demonstrated DNA was mediating the change. |
|
|
Term
|
Definition
| They interpreted Rosy Franklin's ray crystallography data on DNA "double helix". Won the Nobel Prize in 1962 |
|
|
Term
|
Definition
| Demonstrated that genes could move within genetic material-the concept of jumping genes. |
|
|
Term
|
Definition
| The visible accumulation of microorganisms in or on a nutrient medium. Also the propagation of microorganisms with various media. |
|
|
Term
|
Definition
| A single visible colony represents a pure culture or single type of bacterium isolated from a mixed culture. |
|
|
Term
| What are the three types of culturing methods? |
|
Definition
| The Streak method, the dilution method, and the spread plate method. |
|
|
Term
| What are the 3 properties of media |
|
Definition
| Physical state, chemical composition, and functional types. |
|
|
Term
|
Definition
| Agar is added to a liquid medium to solidify. Discovered by Frau Angelina Hesse and enabled Koch to grow bacteria in pure cultures. |
|
|
Term
| What are the 3 physical states of bacteria growth media |
|
Definition
Liquid (broths)- LIquid based. Most common way to culture microorganisms. No guarantee of pure culture.
Semi Solid media- Commonly used to test for motility and to ship microorganisms from one place to another. "slant"- low percentage of agar used.
Solid media- High percentage of agar. Enables formation of discrete, single, colonie. Reliable for pure culture. |
|
|
Term
| What are the different chemical contents of physical media? |
|
Definition
Synthetic- We know exactly what is in the media. Contains pure organic and inorganic compunds that are chemically defined. Some media are minimal other require many more ingredients.
Non-synthetic or complex media- No idea what it contains, we just know that microbes like to grow there. Media contains ingredients that are not chemically defined or pure. Include chocolate and blood agar. |
|
|
Term
| What are the functional types of growth media? |
|
Definition
Enriched media- contains complex organic substances that certain species must have to grow. These organisms are often termed "fastidious". Enriched media is used to to grow fastidious bacteria.
Selective Media- Contains agents that inhibit growth of certain microbes. Selective enables one type of bacteria to grow, while differential media allows bacteria to show different reactions.
Differential media- contains growth agents that promote different phenotype (physical traits) of different organisms on same media.
Media can be both selective and differential media such as MacConkey Agar. |
|
|
Term
|
Definition
| Single agar that can distinguish between 5-7 bacteria based on the color of the colony. |
|
|
Term
| Describe the properties of light |
|
Definition
• Reflection- Light hits an object- reflects away from that object
• Transmission - light goes through an object
• Absorption - only with fluorescence
• Refraction - angle of light being bent.
• Immersion oil
o Wavelength - distance between the troughs or the crest is wavelength. Analogy of resolution as a property of wavelength point is: shorter wavelength= better resolution
• Wavelengths are related to resolution -
o Resolution is the ability to see 2 objects as 2 discrete objects |
|
|
Term
|
Definition
| All have a maximum magnification of 2000X |
|
|
Term
|
Definition
| Most commonly used in labs. Observe live or preserved stained specimens. |
|
|
Term
|
Definition
| Live unstained specimens View an outline of the specimen |
|
|
Term
| o Comaprison of bright field and dark field |
|
Definition
| The condenser of the bright field scope contrasts light ON the specimen and transmit light through the specimen. In dark field microscopy, the condenser deflects the light rays so that the light is reflected by the specimen. |
|
|
Term
| Define; Phase contrast, Fluorescent, confocal, and electron microscopy |
|
Definition
• Phase contrast- Observe live specimen, View internal cell details
• Fluorescent- Fluorescence stain or dye. UV radiation causes emission of visible light from dye. Diagnostic tool.
• Confocal- Flourescence or unstained specimen images are combined to form a three-dimensional image. Usually can look at living samples. Laser that takes optical pictures.
• Electron Microscopy- Most powerful. Very high magnification (100.000X).
• Transmission electron microscope (TEM), you can view internal structure of cells.
• Scanning Electron microscope (SEM)- 3D image |
|
|
Term
|
Definition
- Dye binds to the specimen
i. Simple stain
1. One dye
ii. Differential
1. Two different colored dyes (Gram stain)
iii. Special
1. Emphasize certain cell parts (Capsule Stain) |
|
|
Term
|
Definition
| Dye does not bind to the specimen. Binds to everything around the specimen |
|
|
Term
|
Definition
| Unicellular organisms increase in size to approx two time the original cells and the mother cell divides into two daughter cells and repeat. |
|
|
Term
|
Definition
| The process of dividing and multiplying. With each division the population doubles. Division of the bacterial cell, parental cell enlarges and duplicates its DNA, septum formation divides the cell into two separate chambers, complete division results in two identical cells. |
|
|
Term
|
Definition
| the time requires for a complete division cycle. Length of generation is a measure of the growth rate. Exponentials are used to define the numbers of bacteria of growth. |
|
|
Term
| Describe the phases of the growth curve |
|
Definition
Lag phase- something is lagging in the process of growth
Log phase- Exponential growth. Most active.
Stationary phase- NUmber of living cells is equal to number of dead cells.
Death phase- death. |
|
|
Term
| Enumeration and methods of counting |
|
Definition
An important way to differentiate between living and dead cells. Direct cell count-multiple methods.
Agar Plate- There is a limitation of 30-300 per plate and is the only way to know if they are alive or dead.
Petroff Hauser Counter
Mechanical or automated coulter counter-Constant laser light that counts bacteria as you "pour" it in a tube, but can't tell you whether they are alive or dead.
Turbidity-Cloudy growth media-nothing about whose alive or dead. Good estimate of microbial population |
|
|
Term
| What factors affect microbial growth? |
|
Definition
a. Temp
Psychrophiles (0oC – 15oC) - Obligate (Bacillus globisporus). Mesophile (20oC – 40o C)- Can survive elevated temperatures, but grow best at moderate temperatures. Thermophiles (>45 oC)
b. Gas -Oxygen, CO2
iii. PH- negative logarithim of the hydrogen ion concentration of aqueous solution. Most cells grow between 6-8. Exceptions: Acidophiles (pH 0), Alakalinophiles (pH 10)
c. Osmotic Pressure-Halophiles, Facultative Halophiles
d. Other Factors-Spores and Cysts, Barophiles |
|
|
Term
| What is ecological association? |
|
Definition
| Influence microorganisms have on other microbes. |
|
|
Term
| What are the three types of Nutritional relationships? Describe them. |
|
Definition
o Mutualism- both organisms benefits-Something good happening to both organisms
o Commensalism- one organism benefits- The other one is not being harmed
o Parasitism- host/microbe relationship- At the expense of at least one other organism |
|
|
Term
| What are the four types of transport mechanisms? |
|
Definition
Osmosis
Diffusion
Active Transport
Endocytosis |
|
|
Term
| Describe diffusion and Facilitated diffusion. |
|
Definition
• Diffusion- Net movement of molecules from a high concentration to a low concentration. No energy is expended (passive). Concentration gradient and permeability affect movement.
• Facilitated Diffusion-Transport of polar molecules and ions across the membrane. No energy is expended (passive). Carrier protein facilitates the binding and transport
o Specificity
o Saturation
o Competition |
|
|
Term
| Describe Active Transport. |
|
Definition
• Transport of molecules against a gradient. Requires energy (Active).
• Example. Permeases and protein pumps transport sugar, amino acids, organic acids, phosphates, and metal ions.
• Ex. Group translocation transports and modifies specific sugars |
|
|
Term
|
Definition
• Substances are taken, but are not transported through the membrane. Requires energy (active)
• Common for Eukaryotes- have to change the exoskeleton
• Ex. Phagocytosis, pinocytosis
• Phagocytosis is when the eukaryote’s exoskeleton is changed to absorb molecule. |
|
|
Term
| Describe the four different variations of flagella arrangements that can be on bacteria. |
|
Definition
| (Ex. Monotrichous (one), lophptrichous (multiple flagella on one pole of the bacteria), Peritrichous (whole surface of the bacteria is covered in flagella), and ampphitrichous (multiple flagella on both poles) |
|
|
Term
| Differentiate between 'runs' and 'tumbles'. |
|
Definition
| “Run” is the movement of the bacteria requiring energy. “tumble” is the time in between runs that is “resting period” movement still occurs. |
|
|
Term
|
Definition
| Pili are formed on certain bacteria cells and are important for formation of conjugation bridges for gene transfer (transfer of antibiotic resistance plasmids for example) |
|
|
Term
|
Definition
| Fimbriae are smaller than pili and are important for attachment- E. coli attachment to intestinal cells |
|
|
Term
|
Definition
| o Glycocalyx- Outer coating on bacteria- two types. Capsule and slime layer. Bacteria can go between the two. NEVER BOTH AT THE SAME TIME |
|
|
Term
| Describe the two types of Glcocalyx. |
|
Definition
Capsule
• Protects bacteria from Phagocytosis
• Streptococcus pnuemoniae
• Thick- protection against Phagocytosis. Often associated with virulence. Griffin’s experiments.
Slime layer
• Enable attachment and aggregation of bacterial cells
• Most often associated with the biofilm mode of growth
• Loose surface attachment not very thick. Virulence factor of biofilms. |
|
|
Term
| Describe the cell envelope. |
|
Definition
o Cell envelope- The barrier that separates the environment from the ‘living’ cell.
Composed of cell wall, cell membrane, and gram negative organisms. An outer cells membrane.
Cell Wall= PEPTIDOGLYCAN
Cell membrane= phospholipids- just like us. |
|
|
Term
|
Definition
o Cell Wall- made up of linked N-acetyl glucosamine (NAG) and N-acetyl muramic acid (NAM).
Gram Positive cell wall
• Thick peptidoglycan (PG) layer
• Acidic polysaccharides
• Teichoic acid and liopoteichoic acid
Gram Negative cell wall
• Thin PG layer
• Outer membrane
• Lipid polysaccharide
• Accentuated periplasmic space |
|
|
