BI110 Lecture Notes - Lecture 4: Photomorphogenesis, Phytochrome, Simple Eye In Invertebrates
Document Summary
Photoreceptor basic light-sensing system, found almost universally in all organisms. Phodopsin is the most common photoreceptor in nature. Consists of a pigment molecule (retinal) bound to a protein (opsin) Requires a brain to interpret signals sent from eye co-evolution. Darwin is the most important biologist there ever has been. If numerous gradations from a simple and imperfect eye to one complex and perfect can be shown to exist . Camera eyes evolved by variation and natural selection from a simple primitive eye. Improved eyes give a huge advantage to organism. Read sections on different types of eyes and eye evolution (sections 1. 3c and 1. 3d) Pbs video on the evo of the eye. Phytochrome consists of a protein and pigment called a bilin. One of most important responses that phytochrome is involved is photomorphogenesis. Small portion of spectrum essential for life -> 400-700nm. Also not the right wavelength to excite electrons.
