Term
|
Definition
single cell organism
range in size from mm to nm; can only see individual cells through a microscope
not all are bad- bacteria in stomach
not all can survive alone- biofilms (community of bacteria) or viruses |
|
|
Term
| Major advancements had to be made in order sto study microorganisms |
|
Definition
Microscopes powerful enough to observe microbes
Molecular Biology
Sequencing of genomes |
|
|
Term
|
Definition
Built first compound microscope
Looked at piece of cork under microscope
First to describe cells, but never observed single celled organisms
Published findings in Micrographia in 1665 |
|
|
Term
|
Definition
Father of microbiology
improved the microscope to be able to observe single celled organisms
Referred to them as "animal cubes"
First to describe how heat can kill microbes (coffee)
Died from bacteria he was observing |
|
|
Term
| Franscesco Redi, Lazzaro Spallanzani, Louisi Paseur |
|
Definition
| Important in proving mmicrobes arise from other microbes |
|
|
Term
|
Definition
Italian priest that showed maggots did not spontaneously appear on decaying meat
Showed that maggots only appeared when meat was exposed to flies |
|
|
Term
|
Definition
Italian priest who disproved spontaneous generation of microbes
Sealed flask of sterilized meat did not produce microbes
Critics argued that his experiment did not contain air, so results weren't valid |
|
|
Term
|
Definition
Took Spallanzani's results one step further: Boiled broth then placed in swan necked flask
Flasks allowed air in, but no microbes |
|
|
Term
|
Definition
When he did Pasteur's experiment, he sometimes had growth
Discovered that some organic matter can contain heat-resistant spores |
|
|
Term
|
Definition
Pasteur proposed that the transmission of microbes cause disease
Robert Koch proposed 4 criteria that must be met in order to determine if a microbe causes a disease |
|
|
Term
|
Definition
1.Microbe always present in diseased organism, absent in healthy
2.Microbe isolated from diseased organism and grown in pure culture
3.Microbe isolated must cause disease in healthy organism
4.Re-isolate same microbe from the now-sick individual |
|
|
Term
| Exceptions to Koch's Postulates |
|
Definition
Certain bacteria cause certain diseases
Viruses mutate
Viruses have to have host
Some bacteria can't be cultured in pure form
Some microbes elicit symptoms
Some microbes can cause different diseases |
|
|
Term
| Application of Koch's Posulates |
|
Definition
| Barry Marshall- Hilicobacter pylori causative agent of stomach ulcers |
|
|
Term
|
Definition
| Listerine, aniseptic surgery |
|
|
Term
|
Definition
| Hand washing in hospitals |
|
|
Term
|
Definition
| Penicillin (found by accident) |
|
|
Term
|
Definition
|
|
Term
|
Definition
Can classify by biochemical properties
Woese's three domains of life- based on 16s rRNA, archae are not bacteria, but both prokaryotes |
|
|
Term
|
Definition
Mitochondria were bacteria
Chloroplasts were cyanobacteria
Bacteria internalized into larger cells and lived together (endosymbiosis) |
|
|
Term
| Tools used in microbiology |
|
Definition
| Media, Incubator, Winogradsky column, Centrifuges, Molecular techniques, Microscopy |
|
|
Term
|
Definition
Food or sample for growing microorganisms
Pure culture isolation
Beginning solid media had gelatin
Later used agar (polymer of galactose) |
|
|
Term
|
Definition
Oven used to grow bacteria
Different bacteria grow at different temperatures
Aerobic- require O2
Anaerobic- require no O2 |
|
|
Term
|
Definition
Uses high pressure- 15psi
And Steam- 121 C to sterilize material |
|
|
Term
|
Definition
Most microbes can't grow on typical medium
Used to culture diverse bacterial populations
Mud mixed with shredded newspaper (carbon source)
Gradients depict different bacterial populations |
|
|
Term
|
Definition
DNA sequencing
Restriction Enzymes
PCR
Recombinant DNA
Closing |
|
|
Term
|
Definition
Must be used to identify and characterize individual microbes
Typical bacteria is 1-3 micrometers |
|
|
Term
|
Definition
Light bends as it passes from one medium to another
Refractive index is a measurement of how much light slows down as it passe through a medium
The directin and magnitude of the bend depends on the refractive indices of the two medium (i.e. air and glass) |
|
|
Term
|
Definition
| The shorter the focal length the more magnification |
|
|
Term
|
Definition
ability of a lens to separate or distinguish small objects that are close together
The shorter the wavelength, the greater the resolution
Wider lens closer to specimen can increase resolution
Also immersion oil can increase resolution |
|
|
Term
|
Definition
Bright-field microscop
Dark-field microscope
Phase contrast
Flourescent
Electron |
|
|
Term
|
Definition
produces a dark image against a brighter background
Typically has 3 to 5 objective lenses
We use this type in the lab |
|
|
Term
| The Dark-Field Microscope |
|
Definition
Image is formed by light reflected or refracted by specimen
Produces a bright image of the object against a dark background
Used to observe living, unstained preparations |
|
|
Term
| Phase-Contrast Microscope |
|
Definition
Enhances the contrast between intracellular structures having slight differences in refractive index
Excellent for observing living cells |
|
|
Term
|
Definition
Concept differs from previous microscopes in that the image is seen because of flourescent light emitted from the object
Expose specimen to UV light and forms image resulting from flourescent light
Specimens usually stained with flourochromes |
|
|
Term
|
Definition
Electrons behave like wave lengths
Allows great resolution
Sample must absorb electrons--coat with heavy metal (lenses are magnetic fields)
Transmission and Scanning |
|
|
Term
| Transmission Electron Microscop (TEM) |
|
Definition
Sample is fixed in chemical
Sliced into thin sections
Stained with metal
Very High Resolutions
Good for looking at internal structures |
|
|
Term
| Scanning electron microscopes (SEM) |
|
Definition
SAmple is coated with metal
Used to observe external structure and morphology |
|
|
Term
|
Definition
Most specimens must be fixed onto slide and stained in order to be examined
Heat fixation- preserves morphology but not internal structures
Chemical fixation - used with larger, more delicate organisms
Chemical penetrates cell to preserve internal structure |
|
|
Term
|
Definition
Dyes are used to observe cells
Dyes have two common features
Have chromophore group
Able to bind to cells |
|
|
Term
|
Definition
Uses 1 dye to stain cells
Used to determine cell size, shape, and arrangement |
|
|
Term
|
Definition
Divides bacteria based on different staining properties
Gram staining separates into two groups- gram positive and gram negative |
|
|
Term
|
Definition
Cocci- sphere shape
Bacilli - rod shape |
|
|
Term
|
Definition
Bunches- staphylococci
Chains- Streptococci
Groups of 2- diplococci
Groups of 4- tetrad |
|
|
Term
|
Definition
Single- bacillus
Chains- Streptobacilli
Groups of 2- Diplobacilli
Clusters- Coccobacilli |
|
|
Term
|
Definition
Vibrios = bent shape
Spiral
Irregular |
|
|
Term
| Common Traits of Bacteria |
|
Definition
RNA Polymerase
Ribosomes
Cell wall containing peptidoglycam |
|
|
Term
|
Definition
Many species uncharacterized
Many bacteria cannot yet be grown
Unclassified Organisms- identified solely through rRNA sequence |
|
|
Term
| Deep-branching thermophiles |
|
Definition
Diverged early from eukaryotes
Grown at very high temperatures
Aquifex and Thermotoga - live in near-boiling water
Deinococcus-Thermus -- Lives at lower temperatures
Extremely radiation resistant
Very rapid DNA repair |
|
|
Term
|
Definition
Only bacteria that produce oxygen gas
Many fix nitrogen
Subcellular structures - thylakoids are the site of photosynthesis, similar to chloroplasts
Gas Vessels- used for motility
Many form akinetes - specialized spore cells that survive long periods of dessication and germinate when conditions improve |
|
|
Term
|
Definition
Rods and cocci
No outer membrane but thick cell wall
Many are pathogens (disease-causing) |
|
|
Term
|
Definition
Extremely heat-resistant for millennia
Toxin-formers (botox, tetanus, gangrene
Spore forms inside mother cell |
|
|
Term
| Gram-positive actinobacteria |
|
Definition
Acid-fast cell walls
Waxy lipids in cell walls |
|
|
Term
| Proteobacteria (gram-negative) |
|
Definition
| Largest group - 5 major classes |
|
|
Term
|
Definition
Photoheterotrophs
Endosymbionts
CAuse rocky mountain spotted fever |
|
|
Term
|
Definition
Lithotrophs - nitrate, sulfur, and iron oxidizers
Pathogenic |
|
|
Term
|
Definition
| Lithotrophs- some are phototrophs |
|
|
Term
| Enteric Gamma Proteobacteria |
|
Definition
Facultatively anaerobic rods
Many are motile
Many form biofilms
Pathogens |
|
|
Term
|
Definition
| Some forms attack other bacteria in "packs" - social movement |
|
|
Term
|
Definition
Smallest group of proteobacteria
Helicoptor Pylori- cause of stomach ulcers |
|
|
Term
|
Definition
Spiral shape
Most oxidize nitrite to nitrate |
|
|
Term
| Bacteroidetes/Chlorobi Group |
|
Definition
Obligate Anaerobes- grow only in absence of oxygen
Bacteroids- Major flora of human colon, break down toxins in food, provide food
Chlorobi- Green sulfur bacteri |
|
|
Term
|
Definition
Flexible, narrow spiral shape
Flagella at ends |
|
|
Term
|
Definition
Obligate Intracellular parasites
Larger reticulate body
Grows within cells, cannot survive outside host
Small elementary bodies transfer to new host and can survive outside host, similar in function to spore |
|
|
Term
|
Definition
Multiple internal membranes
Double membrane surrounds nucleoid |
|
|
Term
|
Definition
Irregular shape
Contains tubulin |
|
|
Term
| Bacterial cell structure and division |
|
Definition
Cytoplasm contains compact genome and ribosomes
Cytoplasm is surrounded by cell envelope- includes cell membrane, cell wall (peptidoglycan) and outer membrane |
|
|
Term
|
Definition
Thick cell wall
Thin periplasm
Plasma membrane |
|
|
Term
|
Definition
Outer Membrane
Thin cell wall
thick periplasm
plasma membrane |
|
|
Term
|
Definition
Made of phospholipid bilayer
Proteins embedded in membrane- integral and peripheral proteins, transport materis into and out of cell, senses the outside world, anchor membrane to envelope |
|
|
Term
|
Definition
Protons pushed out cell by pumps
Generates proton motive force
PMF is used to generate ATP- ATP synthase uses PMF for energy |
|
|
Term
|
Definition
move material into or out of the cell
passive transport follows concentration gradient of material
Passive diffusion lets small molecules into cell |
|
|
Term
|
Definition
Not empty space
Contains protein oligosaccharide, salts, and the peptidoglycan |
|
|
Term
|
Definition
Provides strength and rigidity to cell
Sugar chains wrapped in circles around cell
Sugar chains linked to each other by short polymers of amino acids or peptides |
|
|
Term
|
Definition
Composed of phospholipid, Lipopolysaccharid (LPS) and protein
LPS is an endotoxin- elicits immune response |
|
|
Term
|
Definition
Single loop of stranded DNA
Single molecule of DNA
Attached to cell envelope |
|
|
Term
|
Definition
RNA Polymerase transcribes DNA to mRNA
Ribosome translates RNA to Protein |
|
|
Term
|
Definition
Cell elongates as it grows (adds new cell wall at equator)
DNA replicates to make 2 chromosomes
Cell undergoes septation
Binary Division |
|
|
Term
|
Definition
Cyanobacteria have thylakoids
Carboxysomes fix carbon and use energy to make sugar |
|
|
Term
| Inclusion bodies- Intracellular deposits of material |
|
Definition
Glycogen- sugar for energy
PHB (fatty acid polymer) for energy
Polyphosphate to store material
Sulfur for disposal |
|
|
Term
|
Definition
Fimbriae and pili attach cells to surfaces
Secretion systems attach cells to prey
Essential for bacterial pathogemicity |
|
|
Term
|
Definition
Flagella- long, helical protein filaments attached at ends and over whole cell
Flagella rotate to propel cell |
|
|
Term
|
Definition
Movement away or towards a chemical
Chemoattractors cause flagella to rotate counter-clockwise pushing bacteria forward (run)
Chemorepellents cause flagella to rotate (or tumble) clockwise, pushing bacteria away |
|
|
Term
|
Definition
Microbial nutrition
All life requires: Electron flow to drive processes
Energy to move electrons
Materials to make cells |
|
|
Term
|
Definition
Source of electrons
Electron Acceptor
Source of energy |
|
|
Term
|
Definition
Transport proteins are required
Substrate moves along centration gradient; no energy is required |
|
|
Term
|
Definition
Phosphotransferase system
Modifies material as it enters the cell
Used to phosphorylate glucose once it enters the cell |
|
|
Term
|
Definition
Micronutrients- small amounts of nutrients required
Macronutrients- large amounts of nutrients needed
Nutrients required by bacteria differ between species |
|
|
Term
| Ways to obtain pure culture |
|
Definition
Streak Plate- streak cells on plate, agar inhibits spread of microbes on plate, all cells in colony derive from single cell
Dilution of culture in broth- reduces number of cells in each tube, spread liquid on plate to see single colonies |
|
|
Term
|
Definition
Agar plate
Counting Chamber
Spectrophotometer |
|
|
Term
|
Definition
Lag Phase- cells synthesizing materials, not dividing
Log phase= exponential growth
Stationary Phase
Death Phase |
|
|
Term
|
Definition
Cells secrete material to hold to a surface
Cells acting together, cells signal to each other, protects against dispersion, prevents antibiotics from infiltrating |
|
|
Term
|
Definition
Cells respond to changing environment
Endospores- protect against bad conditions, forms inside mother cell |
|
|
Term
| Variations in the environment can impact growth |
|
Definition
pH
Temperature
Osmlarity
Oxygen Content
Pressure |
|
|
