Biology 1002B Lecture Notes - Conjugated System, Channelrhodopsin, Photon
20 Feb 2014
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Document Summary
Photon of blue light (short wavelength) has more energy than a photon of red light (long wavelength: proteins don"t absorb light, pigment absorbs light from the visible spectrum (not damaging) Molecular characteristic of pigments that make them able to absorb light: channelrhodopsin is a protein; it does not absorb light, thus channelrhodopsin must have a pigment associated with it that actually absorbs the light. It is important to note that pigments don"t just float freely; pigments are. Proteins provide organization to pigments: most proteins (ie in mitochondria or cytosol) don"t have pigments associated with them, we usually stain proteins via blue dye. Step 1) photon must be absorbed by the pigment. Step 2) photon excites an electron in pigment from ground state to higher state. There is no intermediate excited state between the blue and the red; the red and blue photons are absorbed, but the green photon is not.
