BIOD 171 module 3 Questions and 100% Accurate Answers GRADED A+ (LATEST UPDATE)

BIOD 171 module 3 Questions and 100% Accurate Answers GRADED A+ (LATEST UPDATE) Immunochemistry - ANS-involves staining of cells to see structures microscopy - ANS-the use of light or electrons to magnify objects Micrometer (um) - ANS-10^-6 m, measures size of cells Nanometer (nm) - ANS-10^-9m, used to measure cellular organelles and viruses Magnification - ANS-the ratio of an object's image size to its real size Resolution of a microscope - ANS-ability to distinguish two objects as separate entities Contrast Microscopy - ANS-shows presence of dye or other treatments Scanning Tunneling Microscope (STM) - ANS-microscope that measures electrons that leak or "tunnel" from the surface of the specimen 0.01nm-10nm can see atoms amino acids DNA and proteins Transmission Electron Microscope (TEM) - ANS-0.078- 100um can see atoms, DNA, amino, proteins, ribosomes, viruses, bacteria and archaea, mitochondria, chloroplasts, human blood cells scanning electron microscope - ANS-0.4-1mm amino acids - red blood cells compound light microscope - ANS-200 nm - 10 mm can see bacteria and archaea, organelles, blood cells, and large protozoa light microscope - ANS-use visible light and blue wavelengths for improved resolution, magnification 1x2000x resolution: 10nm-200nm can see whole cells and organelles electron microscope - ANS-uses electrons with specimens in a vacuum, mag 1000x-100,000x resolution: 1mm - 0.1 nm prokaryotic cells, viruses, macromolecules and large atoms probe microscope - ANS-electron probes that move over the specimen service, mag: greater than 100,000,000x resolution: 0.01nm - 10 nm, 3D surface of macromolecules and atoms Bright-field - ANS-count microorganisms or cells, view stained specimen, view live cells, staining usually required, bright background with clear or colored specimen phase contrast microscope - ANS-view internal structures of live specimens, observe motility, no staining necessary so we can view live specimens, image shows light and dark areas of microbe Dark field - ANS-view living and unstained specimens, filter inhibits light from going through the organism and instead light is reflected by organism, dark background with bright specimen. Fluorescnce Microscopy - ANS-localize specific structures or molecules, diagnostic tool, uses UV light to excite fluorophores, visualize whole cells, specific structures, or proteins and watch movement or interactions, dark backgrounds with fluorescent structures Immunifluorescence - ANS-fluorescent dyes are linked to antibodies which find a cellular target and bind to it bringing the dye that can visualize and locate the structures confocal microscopy - ANS-highly detailed structures, 3D renderings, biofilms, uses a laser to focus plane by plane through the specimen, single plain of structures stained with fluorescent dyes why do we stain microbes - ANS-improves resolution and contrast of a sample for visualization via light microscopy how does a brightfield microscope work - ANS-before the light reaches the sample it passes through a condenser converging the light beams into a focused area on that sample and into the objective lens. After it passes through the objective lens it is directed through the ocular lens or eyepiece the most common power of an ocular lens is 10x How does a phase-contrast microscope work? - ANSusing specialized condensers and objectives, a phase contrast microscope amplifies the differences between cells and the surrounding background to make the cells highly distinguishable How does fluorescence microscopy work? - ANS-take advantage of fluorescent molecules called fluorophores to visualize cells on a dark background, the energy of the incoming light is in the form of ultraviolet spectrum How do confocal microscopes work? - ANS-combine the usefulness of fluorescence microscopy with the ability to visualize cells in 3D unlike light or fluorescence microscopy where light is focused into a single 2D plane. How do stains work? - ANS-stains are salts, which break down into positively and negatively charged ions chromophore is the color in the dye acidic dyes - ANS-anionic (-) chromophores that stain positively charged structures in acidic conditions mostly used for negative staining basic dyes - ANS-cationic (+) chromophores that stain negatively charged structures in basic conditions (high pH), most common dye simple stain - ANS-simple stain is a single basic dye with and involve soaking in the dye for 30-60 seconds and rinsing ex - crystal violet, safranin, fuschin, or methylene blue differential stain - ANS-at least 2 dyes are used to show different cells, structures, or chemicals in a sample and is a multistep process ex - gram, acid-fast special stains - ANS-simple stains that visualize specific structures ex - negative stains, flagellar stains, and fluorescent how does gram staining work - ANS-takes advantage of differences in the bacteria cell-wall, divides bacteria into two groups Gram-positive bacteria - ANS-thick peptidoglycan layer that absorbs crystal violet dye Gram-negative bacteria - ANS-thin inner peptidoglycan wall + outer wall do not retain crystal violet stain and appear pink Gram staining steps - ANS-1 - crystal violet flood for 1 min + rinse with water 2 - iodine flood for 1 min, then rinsed with water 3 - slide is rinsed with ethanol for 10-30 seconds and rinsed with water 4 - safranin flood for 1 min then rinse with water heat fixation - ANS-sample are added to a glass slide and then passed through a flame until all the liquid is removed chemical fixation - ANS-kills the organism negative staining - ANS-acidic dyes (anionic) that are repelled by the negative surface charge of a cell cell remains colorless but background is stained to give a contrast creates a "capsule" effect acid fast staining - ANS-stains mycobacteria and nocardia this is a process used for cells that resist colorization primary dye: carbolfuschin (red) counter stain: methylene blue cell remains colorless but background is stained to give contrast tuberculosis Giesma staining - ANS-detects blood parasites neutral charge giesma: mix of methylene blue, eosin, azure stains nuclei of white blood cells bluish purple and cytoplasm pink diagnosis of malaria and blood protozoa, chlamydia trachomatis, borrelia, histoplasma, pneumocytosis jiroveci cysts