12 Photoreceptors & Rhodopsins Flashcards
During bio-chemical cascade - what molecules are activated by rhodopsin?
G protein molecules
During the photoreceptor function sequence, what stage occurs when the photon is absorbed by the chromophore? (Slide 2)
Photoactivation
How many discs are in one rod cell? (Slide 3)
1000 discs
True or false: all mammals use chromophore as their visual pigment. (Slide 4)
False, all mammals use rhodopsin as their visual pigment.
What determines the number of channels that open during the biochemical cascade? (Slide 6)
cG concentration
Which process in the bio-chemical cascade closes Na channels? (Slide 10)
PDE breaking down cG to GMP by decreasing cG levels
How long does the biochemical cascade last in rods and cones? (Slide 11)
200ms/rods and 100ms/cones
True or FalseElectrotonic spread redistributes Na and depolarizes the cell. (Slide 13)
False
True or FalseSynaptic deactivation occurs when Ca channels are opened and glutamate release decreases. (Slide 14)
False
In a rod, where do the light sensitive molecules reside? (Slide 3)
discs
In a cone, where do the light sensitive molecules reside (Slide 3)
membrane
What has to occur to change the tail structure of 11-cis retinal from bent to straight? (Slide 4)
photon being absorbed by 11-cis retinal
In the dark, about ______ channels open at any one time in each outer segment. (Slide 6)
10,000
True or false: Rods can’t respond to longer wavelength and respond slower than cones. (Slide 18)
True
How many coils you can find in Rhodopsin model? (Slide 22)
Seven coils
