Week 3 Flashcards
(21 cards)
bioremediation
-breaking down cyanite to improve the health of patients
Carl Woese’ classification:
says bacteria contain cell walls
that are made of peptidoglycan(murein)
Carl Woese’ classification:
says archea contain cell walls
when present lack peptidoglycan
Carl Woese’ classification:
says Eukarya contain
protists, fungi, plants and animals
Prokaryotes:
Unicellular microorganisms, genetic material not enclosed with a true nucleus
-includes bacteria and archaea
Eukaryotes:
fungi-unicellular forms include yeasts and molds
-protozoa-unicellular, free living or parasitic
-algae-unicellular forms, photosynthetic eukaryotes
Viruses:
-different from other microbial groups
-need electron microscope to visualize
-celluar organisms w nucleuic acid core sorrounded by a protein coat
-need to use cells.
Characteristics of prokaryotes
-DNA is not enclosed in a membrane: one circular chromosome
-DNA is not associated with histones
-lack membrane bound organelles
-cell walls contain peptidoglycan and are comploicated
-typically divide by the process of binary fission
Pleomorphic=
”shape shifter”,
-micrometer-
typical unit of measurment for microorganisms
-light microscopy
-uses of visible light to observe specimens
-compound light microscopy
=total magnification achieved through a series of lenses
-resolution=
ability of lenses to distinguish between two points a specified distance apart
refractive index
measure of light-bending ability of a medium
Darkfield microscopy
-a specialized form of light microscopy
-image visulized using only REFLECTED LIGHT
-a specimen appears light against dark background
-difficult to stain
Phase-contrast microscopy
-allows detailed examination of internal strucutres in living microorganisms
-based on wave nature of light rays
-brings together both direct light rays and diffracted rays
-image contains regions that are both in phase and out of phase
DIC-differential interference contrast (DIC)
-uses two beams of light each split by seperate prisms
-differences in refractive indexes generates contrast in the image
-higher ressolution than phase contrast
-image appears 3-d
Fluorescense microscopy
-the ability of substances to absorb wavelengths of light and emit lights of longer wavelengths
-specimens can flourese naturally under UV or can be stained w fluorochromes
-flurorescent-anibody(FA), technique or immunoflorescene an be used
Electron Microscopy:
-required to visualize structures smaller than 0.2
-beams of electrons has 100,000 times smaller wavelengths than light
-transmission E.M
-magnifies objects 10,000 to 100,000 times
-requires sectioning and fixing of specimen
SCANNING E.M
-scans specimen with electron beam and magnifies 1000 to 10000x
