Biology 1002B Lecture Notes - Lecture 4: Channelrhodopsin, Photoisomerization, Phototaxis
19 Jan 2017
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Lec #4 - light as energy & information. Structure and mechanism of function of the chlamydmonas eyespot. Uses light to gain information of environment. No vision, b/c vision requires brain, which they don"t have. They can sense light & the direction of where it"s coming from. One must know direction to be phototactic (to move towards/away from light) The phototactic part is a protein found in the plasma membrane- These 2 structures, together, de ne the eye spot. Chlamy. wants to know where the light source is. If light hits the backside, it doesn"t reach channelhhodopsins, b/c the carotenoids act as shields. The only way it can proceed light, is by turning and facing the light. The plasma membrane is polarized (more +"ve on outside) When it opens up, it allows calcium and protons to leak through. (note: it is rare for an ion channel to allow two different ions to leak through).
