Essentials of CBN FINAL (A+ GRADED)

rods prefer.. correct answers darkness turned on in dark and turned off in the presence of light occurs through phototransduction cascade tuns it off rods correct answers rod shaped stack of discs there is much more area for light to hit than in cones more sensitive than cones Cones correct answers cone shaped stack of discs not as much area as rods for taking in information less sensitive than rods phototransduction cascade correct answers how light is turned into electrical energy turns rods off when light is present, which results in activation of bipolar cell, which activates retinal ganglion cell rods: 1) bunch of different proteins (RHODOPSIN) dispersed in disks in rods 2) inside rhodopsin there are 7 subunits that make it up and inside rhodopsin is a small molecule called retinal 3) when light comes in and hits rhodopsin, it causes retinal to change configuration from cis to trans so now rhodopsin also changes shape which is what triggers cascade 4) new rhodopsin shape: 3 subunits: alpha beta and gamma subunits -- new part of molecule as a whole now called transducin - transducin breaks away from rhodopsin 5) alpha subunit comes to the disc again and binds to phosphodiesterase (PDE) -- causes cGMP to convert into GMP which reduces the [cGMP] and increases {GMP] 6) normally cGMP is bound to Na+ channels and allows it to stay open but if [cGMP] is low, the Na channels close and Na can't come in