Biology 1002B Lecture Notes - Lecture 4: Channelrhodopsin, Cell Membrane, Visual Phototransduction
28 Nov 2017
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Class 4 note light as energy & information. Chlamy"s energy usage: chlamy uses light for both energy and information detect light and direction of light (uses the eyespot to gain information from their environment) Phototransduction of eyespot signal: channelrhodopsin drives phototransduction, channelrhodopsin is a protein that sits on the plasma membrane in close proximity to the carotenoid globules, channelrhodopsin is a light-gated ion cannel light triggers the opening of the gate. Absorption spectrum: for an absorption spectrum, you use purified pigment (ex. Chlorophyll, retinal, etc. : you put it in solution in a spectrometer and graph the preferential wavelengths of absorption. For light to be used for energy: the light has to be absorbed, the pigment must also be associated with a protein. Light absorption of chlorophyll: one photon of light excites one electron that"s absorption. January 18th, 2017: excited state electron is easy to oxidize, this gives rise to the absorption spectrum.
