Talk:Rhodopsin

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Hi, This is a good start on the rhodopsin page. Someone needs to expand it a bit (i.e. add 11-cis in front of the first retinaldehyde and add all-trans in front of the second. More important, rhodopsin absorbs green light (500 nm) not purple. Purple is not even a color of light. It results from the eye simultaneously registering red and blue light, which is what you get when you remove the green light from the mixture of colored light we call white. Rhodopsin looks purple because it absorbs green. It would also be good to add that there are lots of invertebrate rhodopsins besides the vertebrate ones. Otherwise, my 25 years of research experience with rhodopsin says you have done an excellent job. Best regards, James W. Lewis

I don't know why Emperorbma believed that rhodopsin absorbed the most at purple. If I understand the descriptions right, rhodopsin is really crimson (purplish-red), which makes sense since its peak absorbance is at a hue I call algæ (green-cyan), at 498 nm. Why can't I find a photograph of rhodopsin? lysdexia 01:55, 23 Nov 2004 (UTC)

[edit] All-trans retinal or a11-trans retinal

"light = 11-cis-retinal -> a11-trans-retinal -> conformational change in rhodopsin -> activate transducin (G protein) -> activate cGMP-phosphodiesterase -> cGMP hydrolyzes -> levels reduced in outer segment -> cGMP-sensitive Na+/Ca2+ channels in PM close -> PM hyperpolarized -> glutamate release inhibited = ø rod cell neurotransmitter released -> detected by bipolar cells -> stimulate ganglion cells -> transmit signal to brain"