Color vision Flashcards
What is color vision
The ability to discriminate a light stimulus as a function of its wavelength
What are the wavelengths of the visible spectrum
380-760 nm
What is monochromatic light
Colored light of a single wavelength
What does remixing of all colors of light create by a prism
the sensation of white
What are the additive primary colors
Blue (435)
Green (545)
Red (700)
These add to produce white color
What are the subtractive primary colors
Yellow, magenta-red, and cyan-blue add up to produce black
What are complementary colors
additive mixture that forms white
what are interference colors
color that results from intereference on thin films like soap bubbles
How can color be produced
through the scatter of white light (blue sky)
What do all human visual pigments share
a common chromophore, related to vitamin A
The rod and cone cell pigments are all complexes of the same chromophore but have different _____
opsin proteins
What are the genes encoding the opsin proteins related receptors of
G protein coupled receptors
What are the G proteins in rod and cone cells callled
transducins
T/F the three c one types share a common transducin
True
What reacts with an opsin protein to form a photoreceptor - pigment complex
11 cis isomer of aldehyde vitamin A
In the _____ state, the chromophore has unique properties that contribute to color vision functioning
opsin bound state
This refers to the change in the absorption of the chromophore when it becomes bound to a particular opsin
opsin shift
What is the point of contact between radiated energy, light and nervous system
Retina
What do rod cells mediate
scotopic (dim light) vision
what do cone cells mediate
phototopic (bright light) color vision
What did the Young-Hemholtz Theory emphasize
Trichromacy and was confirmed by the discovery of 3 cone photoreceptor systems
Is Karl Hering’ opponent theory true? And what was the conclusion
Not true, but his theory was correct in the sense that the signals from the three cone types are combined, not at the pigment level as he had suggested, but at the level of neurons to produce opposing pairs of red-green blue-yeloow, and black-white
Human color vision is _____
trichromatic
T/F The peaks of absorbance vary of three cone types, but their absorbance spectra overlap considerably
TRUE
