ch. 3 Flashcards
? is to see that an object exists, even if u cannot see its details
detection
a microscope is a tool used to ? ? of specimens to enable viewing at a higher ?
increase magnification, resolution
magnification refers to an ? in the apparent ? of a viewed object
increase, size
? is the smallest distance by which 2 objects can be separated and ?
resolution, distinguished
resolution is achieved by ? an image on your ? which is packed with light-absorbing ?
focusing, retina, photoreceptors
rods are sensitive to ? light and allow for ? vision
cones are receptors for ? light and ? vision
dim, peripheral, bright, color
mm
µm
nm
pm
millimeter, micrometer, nanometer, picometer
measurements of:
prokaryotic microbes
eukaryotic microbes
threshold of resolution by the unaided eye
0.4-10 µm
1-40 µm
≈ 150 µm
light microscopy is the observation of a microscopic object based on light ? and ?
?-? microscopy: highlights differences in light passing thru sample
fluorescence microscopy: using ? dyes or proteins under ? light to focus on specific parts of ?
scanning-electron microscopy scans the ? of a sample w ? creating a 3D image of the ?
absorption, transmission
phase-contrast
glowing, UV, specimen
surface, electrons, exterior
transmission-electron microscopy: ? electrons thru thin samples to reveal detailed ? of ? structures
bright-field microscopy: the ? absorbs light and appears ? against ? background
?-? microscopy: dark background used to ? specimen
sends, images, internal
specimen, dark, light
dark-contrast, illuminate
a black box signifies
yellow box signifies
type of microscopy
size of microbes (scale bar)
bacillus is a
bacterium or archaeon w a linear shape
? is a bacterium or archaeon w a spherical shape
coccus
spirochetes is a ? w a
bacterium, tight spiral shape
x-ray crystallography determines the position of ? within a molecule, based on the ? of x-rays by a ?
atoms, diffraction, molecule
light is a form of ? propagated as ?
wavelength is the distance between
contrast is the difference bt.
absorption is the ? of a material to ? light
energy, waves
one peak of a wave and the next wave
light and dark
capacity, absorb
reflection is the ? of light or sound waves after they hit an object; when light bounces off an object; the angle at which the light hits the object (? ?) and bounces off a surface (? ?)
return, incident angle, reflection angle
refraction is the ? and ? of light as it passes thru a substance
the refractive index is the speed of light in ? divided by the speed of light in ?
bending, slowing, vacuum, medium
scattering occurs when the ? of ? light is scattered in ? direction
finish: magnification requires
fraction, incident, all, refraction
focal ? is the point at which light rays ? after passing thru a lens
focal ? is the plane that contains the ? ? for a given lens
point, intersect, plane, focal point
empty magnification occurs when there is ? w/o an increase in ?
magnification, resolution
objective lens: lens closest to ? and generates ?
numerical aperture =
immersion oil is used to improve image ? by reducing ? loss
specimen (object), magnification, NA= refractive index of medium times sine of angle, clarity, light
the compound microscope was invented by ? ? and has ? lenses to increase ?
Robert Hooke, multiple, magnification
parts of compound microscope:
condenser: ? light to improve image ?
diaphragm: controls ? of light passing thru
parfocal occurs when the microscope stays in ? when ? ?
focuses, clarity, amount, focus, switching lenses
total magnification = mag of ? times mag of ? ?
depth of field refers to the ? of the area in focus
wet mount is used to view ? microbes by using ? to keep it hydrated while studying the specimen
eyepiece, objective lens
thickness
living, water
? preserves and stabilizes microorganism, helping to enhance ?
fixation, detection
staining is used to ? the cells using dyes, helping to increase ? and image ?
color, resolution, clarity
a ? stain is a staining technique that uses multiple dyes to differentiate between different ? of cells or cell ? by visually contrasting them with different ?
differential, types, structures, colors
the gram-stain was invented by Hans Christian ?; its purpose is to differentiate bt 2 types of ?
Gram, bacteria
characteristics:
gram-positive
gram-negative
thick wall, purple/blue, no outer membrane
thin wall, pink/red, possesses outer membrane
fluorescence is when a molecule ? light at ? (color) and emits light at a ? wavelength (different color)
absorbs, wavelength, different
counterstain uses a dye called ?; it allows the visualization of gram-? material
safranin, negative
acid-fast stain is used to identify ? with ? walls that resist staining
endospore stain is used to color ? ? which resist heat and ?, making it visible under a microscope
negative stain stains the ?, leaving cells clear and ?, used for delicate cells
antibody stains use ? to detect and identify specific microorganisms or cells
bacteria, waxy
bacterial spores, chemicals
background, outlined
antibodies
fluorophore is a molecule that ? ? at one wavelength and ? light at a longer wavelength
absorbs light, emits
?, ‘‘false color’’, is the process of adding color to a sample to illuminate it
artifacts are ? ? ?
colorization
incorrectly interpreted structures
