BIOLOGY 1AL Lecture Notes - Lecture 3: Aliivibrio, Chemiluminescence, Quorum Sensing
Document Summary
->fluorescence: light emission from a molecule after it has been excited by prior absorption of electromagnetic radiation. ->epi-fluorescence microscope: light source that"s on the side, puts out some range of wavelengths, passes through an excitation filter, lets one wavelength go through. ->light bounces down and goes through objective, focuses light onto specimen. ->dichroic mirror (two colors)-->chosen for each set of exciting and emitting wavelengths-->reflects shorter wavelength, but emission filter absorbs longer wavelength. ->leech embryo with red and green fluorescent lineage tracers and blue fluorescent dna counterstain. ->production of light from a chemical reaction involving a light-producing molecule (luciferin), and an enzyme (luciferase), often with other co-factors. ->bioluminscence has evolved at least 40 times independently, in more than ten different phyla. ->luciferase and luciferin are defined functionally, not as specific chemical compounds/enzymes. ->squid emits light of its own, hides shadow, looks light stars, stealth approach for squid to evolve in order to avoid predation.
