Karteikarten
Microbiology Chapter: 2
Karten in diesem Stapel (64)
- 1The longer the wavelength...The shorter the frequency
- 2What are the 3 major properties of light?-Wavelength
-Frequency
-Amplitude - 3The shorter the wavelength...The higher the frequency
- 4ReflectionWaves bounce off and produce the colors we see as a reflection.
- 5AbsorbanceLight is absorbed by an object
- 6TransmittanceAmount of light passing through an object/substance
- 7How do we get color?All visible light is absorbed by an object, but the light that is reflected is the color we see
- 8How does a spectrophotometer work? Why do we use it in microbiology?It measures transmittance of a sample. Therefore, a spectrophotometer can measure bacterial growth by looking at the transmittance of a bacterial sample.
- 9What types of interference is there?Constructive and destructive
- 10Constructive interference2 or more waves with crests aligned that crash together and create a higher amplitude
- 11Destructive interferenceCrest of 1 wave meets the trough of another leading to a lower amplitude
- 12DiffractionScattering or bending of light that gets larger when obstacle or opening is smaller than wavelength that can result in interference
- 13Diffraction is relative to the......size the of the opening of the obstacle.
- 14RefractionLight waves change direction inside of a new medium.
- 15Refractive indexHow much a material slows transmission
- 16What happens to light when it changes mediums?Light will change directions, be reflected, or refractive
- 17LensesAn object that collects light and refracts it to a single point
- 18What are the two types of lenses?-Convex
-Concave - 19Convex lensRefracts light to a focal point in the lens
- 20Concave lensRefracts light away from a focal point in the lens
- 21How does the human eye use a lens? How can an artificial lens help?It focuses reflected light through a lens onto the retina. An artificial lens can focus or change an image before it reaches the eye's lens.
- 22HyperopiaFarsightedness; too little curvature in the eye lens
- 23MyopiaNearsightedness; too much curvature in the eye lens
- 24How do fluorescent dyes work?They absorb UV or blue light and use the energy absorbed to emit photons of different colors.
- 25What role do electrons play in florescence?Electrons grow to higher energy states as light is absorbed, then when the lights are turned off, electrons fall back to ground states which emits energy.
- 26When does phosphorescence occur?When photons are released after a delay for absorption.
- 27MagnificationLens used to enlarge an image
- 28ResolutionThe measurement of how sharp an image is
- 29How does wavelength effect resolution?The shorter the wavelength, the better the resolution.
- 30What is numerical aperture?The ability to gather light
- 31What is contrast? Which part of the microscope effects this?The difference in light intensity; Iris diaphragm
- 32What type of microscope did Leeuwenhoek use to discover his microorganisms?A simple microscope (one lens)
- 33Who invented the compound microscope? How does it differ from a simple microscope?Galileo; It has two lenses
- 34Which microscope did Hooke use? What did he discover?Hooke used a compound microscope; He discovered "cells"
- 35ChromophoresPigments that absorb and reflect light in a light microscope.
- 36Describe the bright field of a light microscope-It can be mono or binocular
-Uses the objectives and ocular lenses
-Requires oil immersion to increase resolution - 37Describe the dark field of a light microscope-It is a small opaque disk that blocks the illuminator
-Produces a hollow "cone" of light that is refracted or reflected by the specimen
-Creates high contrast, high resolution images
-Useful for live specimens - 38What is phase contrast?Used refraction and interference within a specimen to produce a high contrast, high resolution image within a staining.
- 39How can immunoflorescence be used to help in diagnosing people?By using flourochromes attached to antibodies, a seeable light is bound to an antigen or structure of interest.
- 40Direct immunoflouresenceA flourochrome attached to an antibody binds directly to an antigen
- 41Indirect immunoflouresenceFlourochrome is attached to a secondary antibody that binds to a primary antibody which directs to the antigen
- 42How does an electron microscope work?-Uses excited electrons to create high resolution images due to the shorter wavelengths of electrons
-Can see sub-cellular/molecular structures
-Uses magnets instead of lenses to focus light - 43TEM (Transmission electron microscope)Allows for viewing of internal structures
- 44SEM (Scanning electron microscope)Allows for viewing of surface structures
- 45STM (Scanning tunneling microscope)Allows for imaging of surfaces at the atomic level
- 46AFM (Atomic fore microscope)Extremely high resolution type probing microscope
- 47What are stains?Positively and negatively charged ions mixed with salts
- 48What is a chromophore?A colored ion
- 49What takes up a positive stain?Cells/Organims that is the specimen
- 50What takes up a negative stain?The background
- 51What is the 3 things to remember when creating a slide?-Smear
-Fix
-Stain - 52Simple StainUses a single dye for contrast and for viewing particular structures in a specimen.
- 53Differential StainUses more than one dye to help distinguish between different organisms
- 54The Gram StainUsed to differentiate different bacteria based on cell wall composition
- 55What is the first step in Gram Staining?The primary stain, crystal violet, is added to the smear. It will stain all cells purple/blue.
- 56What is the second step in Gram Staining?The mordant, Iodine, is added which makes the dye less soluble and is more likely to adhere to the cell walls. Cells remain purple or blue
- 57What is the third step in Gram Staining?Alcohol is added to the smear to act as a decolorizer that will wash away stain from gram negative cell walls. Gram-Positive cells remain purple or blue and Gram-Negative become colorless.
- 58What is the fourth step in Gram Staining?The counter stain, Safranin, is added which will adhere to the cell walls of Gram-Negative cells. Gram+ is now purple/blue and Gram- is now pink/red.
- 59Why do we do acid fast staining?Used to differentiate between Gram + cells that may or may not have mycolic acid in the cell walls.
- 60What agents are used in acid fast staining?-Carbolfuchsin
-Methlylene Blue - 61Why do we do a capsule stain?Capsules are often linked to virulence, so they are important diagnositic tools. They do not absorb normal dyes so a negative stain is used with nigrosin or india ink.
- 62The Schaefter-Fulton method:Used for endospore identification. Uses heated malachite green and a counter stain of safranin because endospores do not take up primary stains.
- 63Flagella StainUsed to identify numbers and position of flagella. Does not include heating, as it will destroy flagella.
- 64—
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- Micriobiology Karteikarten am Microbiology Chapter: 2, erstellt von Hannah Fisher am 27/01/2018.
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