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Microbiology Test 1 Campbell
Chapters 1-4
130
Microbiology
Undergraduate 3
09/15/2015

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Term
What is microbiology?
Definition
Microbiology is the study of organisms which are usually seen by a microscope, not the unaided eye.
Term
Prokaryotic vs. Eukaryotic
Definition
Prokaryotic cells came into existence before the eukaryote. They do not have membrane bound organelles or a nucleus. Eukaryotic cells have a nucleus and membrane bound organelles
Term
Carl Woese
Definition
He created Domain, which is used as a classification system. It showed 2 distinct types of groups, Bacteria and Archaea
Term
Prokaryotes
Definition
Majority have cell wall with peptidoglycan. Reproduce by binary fission. About 0.3-5 nanometers.
Term
Significance of Cyanobacteria
Definition
produces significant amounts of oxygen; photosynthetic
Term
Archaea
Definition
Distinguished from bacteria by unique rRNA gene sequences. Lack peptidoglycan in cell walls. Have unique membrane lipids. Many live in extreme environments (hydrothermal vents, dead sea)
Term
Protozoans
Definition
unicellular, motile, sexual and asexual reproduction
ex: phytoplankton (photosynthetic)
Term
Algae
Definition
unicellular and multicellular
photosynthetic
Term
Fungi
Definition
unicellular and multicellular
Ex: yeast
Term
Multicellular Parasites
Definition
Helminths- parasitic worms
ex: roundworms, flatworms, flukes
Term
Are virus' considered organisms
Definition
No, they are considered infectious agents
Term
Viruses
Definition
Obligate intracellular agent
Consists of either DNA or RNA, surrounded by a protein coat
Term
Viroid and Virusoids
Definition
Consist of only RNA; no protein coat
Term
Prions
Definition
consists only of protein, no DNA or RNA
ex: Mad cow disease
Term
Why did RNA exist before DNA?
Definition
RNA was first because it could store information and was catalytic and DNA is NOT catalytic, only a storage molecule
Term
The Endosymbiotic Theory
Definition
The theory that states that mitochondria and chloroplasts were acquired to the eukaryotic cell by endosymbiosis from a prokaryotic cell.
Term
Who developed the Endosymbiotic Theory?
Definition
Lynn Marguilis
Term
Why are microorganisms important for vital activities?
Definition
Essential for environmental health
Normal flora keeps you healthy
Term
What is normal flora?
Definition
Bacteria that is good in one place but bad in another. 500-1000 species of bacteria reside in and on the body. Bacteria outnumber cells 10:1
Ex: E. Coli
Term
Why is nitrogen important for DNA?
Definition
Nitrogen Fixation
Term
Why did the biosphere not work?
Definition
There was too much bacteria taking up all the oxygen
Term
Antony Van Leeuwenhoek
Definition
improved microscopy
Increased magnification 50-300x
Term
What is spontaneous generation?
Definition
the belief that living organisms can develop from non-living matter
Term
Who challenged spontaneous generation and what did he do?
Definition
Fransesco Redi challenged spontaneous generation and he did this with the meat and maggots experiment
Term
Who tried to disprove Redi? What did he do?
Definition
John Needham- he used broth
Term
Who disproved Neeham?
Definition
Spallanzani disproved Neehams experiment because he found a flaw in it.
Term
What did Louis Pasture do?
Definition
He created the S-curved flask to trap bacteria, but it still allowed oxygen in
Term
What is Koch's Postulate?
Definition
1. Present in every case of the disease. absent in healthy organisms
2. Must be isolated and grown in pure culture
3.Same disease must result upon infection of healthy organism
4.Same microorganism must be isolated again
Term
Why was gelatin an issue when doing cultures?
Definition
Some bacteria eat gelatin
Term
What are some application of microbiology?
Definition
Sewage Treatment
Bioremediation (ex. oil)
Produce useful products (ex. insulin, ethanol, amino acids, pesticides)
Genetic Engineering
Food (lactic acid, fermentation reactions)
Term
Rank microorganisms smallest to largest
Definition
virus, bacteria, protist, eurkaryote
Term
How can viruses be seen?
Definition
Through an electron microscope
Term
Resolution
Definition
the ability to distinguish between separate objects
Term
Contrast
Definition
light intensity difference between a sample and its background
Term
Light Microscope
Definition
Any microscope that uses light
Term
Ocular Lens
Definition
the lens that is looked through
Term
Objective Lens
Definition
One near the slide
Term
Parfocal
Definition
describes the microscope staying relatively focused as magnification increases
Term
Parcentric
Definition
slide remains centered as magnification increases
Term
Bright Field Microscopy
Definition
the image is darker than the background. Lenses are causing convergence. The convex lens focus the light (focal point), distance between the lens and F is the focal length
Term
Resolving Power
Definition
the minimum distance between 2 objects with them still observed as separate entities. As resolution becomes better, resolving power decreases
Term
What factors impact resolutions path of light? (resolution dependent on)
Definition
Quality and size of lens
Oil Immersion
Wavelength
Term
Numerical Aperture
Definition
A measure of the cone of light entering into the objective lens
Term
Working Distance
Definition
distance between the edge of the objective lens and the surface of the specimen
Term
Relationship between oil and glass
Definition
They have the refractive index
Term
Wavelengths relation to resolution
Definition
Short wavelengths increase resolution because they can fit where longer wavelengths cant
Term
Average wavelength for visible light
Definition
about 500 nm
Term
What are stains composed of?
Definition
A chromophore
Charged salt- negative dye = acidic pH
positive dye = basic pH
Term
Which type of dye is used as a negative stain?
Definition
Acidic
Term
What do stains do?
Definition
Increase visibility
Accentuate morphological features
Preserve specimens for future study (heat)
Term
Heat fixation
Definition
The internal and external cell structures are preserved. This kills the organism, inactivates the enzymes, toughens cell structures.
Term
Simple Stains
Definition
usually a basic dye, stains all bacteria the same color
Term
Differential Stains
Definition
Distinguishes between different types of bacteria
Gram stain and Acid Fast stain
Term
The Gram Stain
Definition
Step 1: Add crystal violet, primary stain and makes everything purple
Step 2: Add iodine, mordant, makes everything bigger
Step 3: Alcohol Wash, decolorizes
Step 4: Add Safranin, counterstain
Term
What makes something Gram+ or Gram-
Definition
Gram positive indicates a thick cell wall, the crystal violet and iodine mixture is not able to escape from the thick peptidoglycan layer. The opposite is true for Gram-
Term
Acid Fast Staining
Definition
Acid fast is bacteria containing numerous waxy lipids (mycolic) in their cell walls. 1. Carbolfuchion and heat 2. Decolorize by acid alcohol 3. Counterstain Methalyne Blue
Term
Special Staining
Definition
Used for staining specific structure inside/outside of the bacterial cell
Term
Moellar Stain
Definition
A type of endospore stain
1. Carbolfushion and heat
2. decolorize
3. Counterstain with Methalene Blue
Term
Schaeffer-Fulton Stain
Definition
A type of endospore stain
1. Malachite Green + heat
2. Decolorize
3. Safranine counterstain
Term
Capsule Stain
Definition
A negative stain
India ink is used which is an acidic dye
Term
Flagella Stain
Definition
A mordant is used to make them appear thicker
Term
Dark Field Microscope
Definition
Staining not required
Dark background, bright organism
collects only the light reflected and refracted by the ORGANISM
This is used for eukaryotic cells and larger bacteria
Term
Phase Contrast Microscope
Definition
No staining is required
Increases contrast by slowing down some wavelengths
Good for prokaryotes
Has 2 types of rings- annular: directs light around and through the specimen
phase: increase the contrast of light waves by speeding them up
Term
Fluorescence Microscopes
Definition
UV light source
Excites fluorochromes
Fluorescent dyes
Term
Confocal Microscopy
Definition
Laser examines 3D objects in multiple planes by a computer
Normally fluorescently stained
Term
Electron Microscopy
Definition
Uses electro magnetic lenses and electrons
Magnifies 10,000-100,000 times
Term
Transmission Electron Microscopy
Definition
Must be used under a high vacuum because air deflects
Denser regions appear darker due to more electron scattering
Term
Sample Preparation for TEM
Definition
Sample must be embedded, dehydrated, soaked in plastic
Negative stain is possible with TEM as well as shadowing and freeze etching
Term
TEM vs Scanning EM
Definition
TEM: radiation passing THROUGH a sample
SEM: electrons released from the sample SURFACE
Term
Scanning Probe Microscopes
Definition
Most powerful
The surface is so sharp, it can touch individual atoms
Term
Shape of a coccus bacteria
Definition
Round
Term
Shape of a bacillus bacteria
Definition
Rod
Term
Shape of a Spirillum bacteria
Definition
wavy
Term
Shape of a coccobacillus bateria
Definition
round and rod
Term
Shape of a Vibrio bacteria
Definition
comma shaped, uncommon
Term
Shape of a spirochete
Definition
spiral, uncommon
Term
What is a chain
Definition
Cell arrangement where there is a single chain in one plane
Term
What is a packet
Definition
Cell arrangement where there are 3-D clumps in two planes
Term
What is a cluster
Definition
Cell arrangement where the bacteria are in several planes at random
Term
What is the composition of the cytoplasmic membrane?
Definition
It is made up of a bilayer of phospholipids. It is amphipathic- there is a different chemical feature on both sides. There is also a lipid bilayer with hydrophilic heads and hydrophobic tails
Term
What is the fluid mosaic model?
Definition
The word fluid tells us that the membrane is not static, it can more and adjust or else cells pop. It has LATERAL movement and rotation. Mosaic tells us it is not uniform throughout the membrane.
Term
What is flip-flop?
Definition
It is a rare occurance when the fluid mosaic model moves up and down. The enzyme that makes this happen is flippase. The reason this is rare is because there is a lot of resistance from the non-polar tails to move to the other size of the cell
Term
Describe an Integral protein
Definition
Goes through both sides
Makes up 70-80% of protein in the cytoplasmic membrane
Not easily extractable
Insoluble in water
Have some hydrophilic regions
Term
Describe a Peripheral protein
Definition
On the inside or outside of the membrane but never both. If on the inside they are normally helping another protein and if they are on the outside they are working as receptors
20-30%
Easily Isolated
Soluble in Water
May attach to integral proteins
Term
What is true about both a peripheral protein and a integral protein?
Definition
The both function as receptors for cell signaling. Both may interact with cell wall. Both are transporters of nutrients
Term
Functions of the cytoplasmic membrane
Definition
Selective Barrier
Site of Transport Systems
Site of Crucial metabolic processes
Site for special receptors to decent environmental conditions
Term
What compounds are passive transport limited to?
Definition
H2O, O2, CO2, and small nonpolar molecules
Term
Describe Facilitated Diffusion
Definition
Controlled by shape, depends on a concentration gradient, less important in prokaryotes
Term
Describe the two types of active transport
Definition
Primary- utilizes ATP and are uniporters
Secondary- utilized gradients and are symporters and antiporters
Term
Primary Active Transport
Definition
ATP Binding Cassette Transports
Found in bacteria, archaea, and eukaryotes. If it is gram negative the protein will attach to the periplasm but if it is gram positive it will attach to the lipids
Term
Secondary Active Transport
Definition
The proton motive force is used here which is the respiratory chain in the membrane pumps protons out setting up a concentration gradient
Term
What are the 3 types of electrochemical gradients?
Definition
Uniport- 1 thing, 1 direction
Symport- 2 things 1 direction
Antiport- 2 things, opposite directions
Term
What are the steps of phosphorylation?
Definition
PEP donates phosphate to E1, pyruvate is left over
E1 is going to pass the phosphate to HPr
Phosphate goes E2a and then to e2b
Then it is passed to glucose
E2c is the transmembrane protein to where the glucose can get in but not out without the phosphate (ex. ticket booth), Glucose + phosphate = glucose 6-P
Term
What are siderophores?
Definition
compounds secreted by bacteria that scavenge for iron and facilitates its uptake. Iron is brought back to the bacteria and absorbed.
Term
Describe ABC when it comes to iron transporters
Definition
siderophores sit in the periplasm once in the cell
once it gets into the cytoplasmic membrane it pulls the iron into the cell against its gradient
the cell releases iron from the siderophore, making it able to be used
Term
What are some environmental hardships cells can go through
Definition
changes from aqueous to hot and dry
Isotonic to hypertonic or hypotonic
Term
What are mycoplasma?
Definition
They live in environments that are friendly to their outer membranes. They use hopanoids to deal with turgor pressure
They DO NOT handle environmental changes well!!
Term
What is peptidoglycan?
Definition
Strands of polysaccerides that are weaved together of the cell membrane. This is unique to bacteria. This weaving provides strength to the cell wall. A tetra peptide provides the crosslinking
Term
What are some functions of the cell wall?
Definition
Cell Shape
Protection
Nutrition
Temperature
Term
What is the backbone of the cell wall?
Definition
Alternating Monomers of NAG and NAM which pack into each other in numerous layers
Term
How are NAG and NAM related to glucose?
Definition
The OH is replaced with an acetyl group
NAM picks up the acetyl group
NAG picks up the acetyl group as well as a lactyl group
Term
Describe Gram - cell wall
Definition
Has DAP
Has direct D-ala binds to Dap
Starts link with D-ala
Very thin cell wall, about 2-3 layers
Periplasm is more defined
Has 2 periplasms
Term
Describe Gram + cell wall
Definition
Has L-lysine
Does not have a direct link. 5 glycine residues in a row connect D-ala to L-lysine. This is the peptide interbridge called penta glycine
Starts link with D-ala
Thick cell wall, 30 or more layers
Periplasm is harder to see
Does not have an outer membrane
Only 1 periplasm
More resistant to osmotic pressures
Has teichoic and lipteichoic acids
Term
What are tehichoic and lipteichoic acids?
Definition
They are anchoring compounds in a Gram + cell wall. They add additional support to keep the peptidoglycan layers toether. Teichoic is within the cell wall and lipoteichoic is between the cell wall and the cell membrane. They carry a lot of negative charge
Term
What is the LPS?
Definition
The LPS is a lipid attached to a polysaccharide or series of sugars.
Term
What 3 areas can the LPS be broken up into?
Definition
The lipid- disaccharide of glucosamine with 3 FA attached
The Core Polysaccharide- Carbohydrates attached to lipid by KDO
0-Specific Polysaccharide- Species and strain specific
Term
What is an endotoxin?
Definition
When the macrophages in the bodies immune system target the LPS, it can tear apart the lipid A from the sugar tail, and if the body doesn't handle it it is very toxic, like anaphylactic shock
Term
What is endotoxin's benefit to bacteria?
Definition
It works as a protective layer
It functions as virulence (survival in humans)- rise in temperature can be a better environment, breakdown of cells is food. It confers negative charge in the bacteria
Term
What is a channel protein?
Definition
diffusion of small hydrophilic molecule, can be different sizes based on selective entry of differently sized molecules
Term
What is Braun's Lipoprotein?
Definition
Connects the outer membrane to the cell wall. Works kind of like techoic acid. It really is focused on anchoring the outer membrane.
Term
What does the ethanol do in the Gram staining process?
Definition
It dehydrates the membrane!
Term
What is glycosidase?
Definition
It breaks down the cell wall of bacteria in your eye (Lysozyme). It breaks down the sugar linkages in peptidoglycan and breaks the bonds between NAG and NAM
Term
What are beta-lactam antibiotics?
Definition
An example of these antibiotics is penicillin. These type of antibiotics do NOT break down the cell wall, but they prevent the cell wall from growing. This antibiotic prevents cross linking. The weakened cell wall then ruptures and falls apart.
Term
What are protoplasts?
Definition
Protoplasts are Gram + bacteria that do not have a cell wall, the cell membrane of this remains in tact. Protoplasts are sensitive to osmotic changes
Term
What are spheroplasts?
Definition
they are gram negative cells without the cell wall. The cell membrane and the outer membrane are still in tact
Term
What is special about the mycobacterium's cell wall?
Definition
The mycobacterium have an additional layer with mycolic acids. These are anchored by arabinogalactins to the peptidoglycan layer. There can also be a capsule on this bacteria. That gives the bacteria 4 layers of protection. This is why it is so hard to treat tuberculosis. To the hydrophobic nature of mycobacterium, it will always stain gram- even when its gram+, so acid fast staining is used instead
Term
What are components of the internal prokaryotic cell structure?
Definition
Storage Granules- "inclusion bodies"
Organic Material
Inorganic Material- magnetosomes
Gas vacuoles
Nucleoid
Plasmids
Ribosomes
Term
Why are gas vacuoles important in prokaryotic cell structure?
Definition
They are important for floating. In a bacteria like cyanobacteria, the gas collects from the environment to create a gas balloon to float up and collect more energy
Term
Why are nucleoids important in prokaryotic cell structure?
Definition
They are where genetic information is organized. They are generally circular geneomes comprised of just one chromosome.
Term
Why are plasmids important in prokaryotic cell structure?
Definition
Plasmids are small portions of DNA that can be exchanged bacteria to bacteria
Term
Why are ribosomes important for prokaryotic cell structure?
Definition
Since the ribosomes are not bound by an envelope, everything can happen at the membrane which makes the process really fast
Term
What are some components of the external structure of prokaryotes?
Definition
Glycocalyx
Fimbriae and Pili
Flagella
Term
What is the glycocalyx?
Definition
it is a sugar coat on the outside of the prokaryote. It acts like an invisibility coat and is sticky. There are 2 types: capsule and slime layer. The capsule is tightly attached and organized, the slime layer is loosely attached and unorganized.
Term
What is the function of pilli and fimbriae?
Definition
Pilli- genetic exchange
Fimbriae- just attachments, just kind of there
Term
What are the patterns of arrangement for flagella?
Definition
Monotrichous- only one flagella on either the left or right side
Amphitrichous- one flagella on both sides
Lophotrichous- a tuffed piece on one or both sides
Peritrichous- flagella all over
Term
What is the structure of the flagella?
Definition
Basal Body --> Hook --> Filament
Term
What is the filament?
Definition
It is the tail of the flagella and it coils to leave a hollor center
Term
What is the hook?
Definition
The hook connects the filament to the basal body
Term
What is the Basal Body?
Definition
anchors flagella into the cell wall and cytoplasmic membrane, it gives the filament the ability to move
Term
What is the difference between a flagella in gram + and gram -
Definition
In gram positive there is only one set of rings (M and S), and they sit in the membrane. The hook goes through the peptidoglycan.
In gram - there are two sets of rings: (M and S: P and L). The M and S sit in the membrane, the hook is attached to the outer membrane, and the P goes through the peptidoglycan and the L goes through the outer membrane
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