Biology 1002B Lecture Notes - Lecture 23: Lysine, Continental Drift, Food Choice
11 Apr 2017
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Underlying structures (tissue types) and functions are very different: evolved many times independently (at least 40 times, non homologous. Convergence to something that functions and looks similar o o. Huge advantage to be able to perceive advantage. Many paths to get to end result (eye) Evidence in homology: all have opsin, rhodopsin, crystallins (group of proteins that make the clear lens of eye) Crystallins are homologous to heat shock proteins (share common ancestor: pax6 is a transcription factor required in the development of all eyes. Domains with specific functions in specific regions are highly conserved in every pax6 homolog. Cone cell senses light (colour vision) o o. They are cells that absorb photons of light, but still contain all the basic organelles. What accounts for differences in absorption spectra of different opsins. Biophysical basis of colour vision: all forms of opsin have the same type of retinal, differences in the way retinal is bound to protein.
