HOME PAGE * KS3 SCIENCES * GCSE BIOLOGY CHEMISTRY PHYSICS * ADVANCED LEVEL CHEMISTRY

Advanced Level Organic Chemistry: UV and visible light absorption spectroscopy - human eye pigments

Scroll down and take time to study the content and/or follow links or [Use the website search box]

Doc Brown's Advanced Chemistry: PART 15.5 uv and visible light absorption spectroscopy - human eye

Doc Brown's Chemistry Advanced Level Pre-University Chemistry Revision Study Notes for UK IB KS5 A/AS GCE advanced A level organic chemistry students US K12 grade 11 grade 12 organic chemistry courses Spectroscopic methods of analysis and molecular structure determination

SPECTROSCOPY INDEXES  *  All Advanced Organic Chemistry Notes  *  [WEBSITE SEARCH BOX]

15.5.1 The origin of colour, the wavelengths of visible light, our perception!

15.5.2 uv-visible spectroscopy theory, spectrometer, examples of absorption & reflectance spectra explained

15.5.3 uv-visible absorption spectra - index of examples: uses, applications, more on the chemistry of colour

email doc brown * Use mobile phone/ipad etc. in 'landscape' mode * This is a BIG website, take time to explore it


The uv-visible light absorption spectra of the photopigments of the human eye.

The human eye has an amazing range of photopigments that respond to visible light photons.

uv-visible light absorption spectra photopigments of the human eye spectrum of red cones green cones blue cones rods wavelengths of maximum absorbance

Image from https://www.quora.com/What-if-our-eyes-could-see-beyond-the-visible-spectrum-Would-we-discover-more-colours

The uv-visible light absorption spectra of the photopigments of the human eye.

The photopigments of the eye are sensitive to the whole range of visible light photons and each individual pigment is sensitive to its own particular range of the visible spectrum - their own narrower range of visible light photons (listed below).

The cone cells are adapted to detect bright light and bright colours from three different type of photoreceptor proteins called opsins - examples of natural photopigments.

Cones contain opsins called iodopsin, porpyrosin and cynaopsin and the different proportions of them enable the three types of cones to be particularly sensitive to a narrower range of visible light photons. You can see there is quite an overlap in the three cone spectra.

The red cone cells are most sensitive green-yellow-orange-red photons,  λmax of 565 nm (yellow).

Iodopsin is particularly sensitive to red light - a greater proportion of it in a red sensitive cone cell.

The green cone cells are most sensitive to blue-green-yellow photons, λmax of 530 nm (green-yellow).

Cyanopsin is particularly sensitive to blue-green photons - a greater proportion of it in green cone cells.

The blue cone cells are most sensitive to violet-blue photons, λmax of 420 nm (violet) and detect lowest wavelengths of visible light.

The rods are most sensitive to violet-blue-green photons, λmax 495 nm blue-green (cyan).

The rods only contain the photopigment rhodopsin and are much more sensitive than cones and are adapted for us to see in dim light.

Rhodopsin is light sensitive substance formed from the protein opsin and 11-cis-retinal and can be triggered by a single photon.

Cone cells cannot detect colour by themselves; we perceive colour vision by the brain comparing signals from across the different cone types.

For more on the photochemistry of the eye see Cis/trans retinal - biochemistry of the eye

To add note on colour blindness?


Key words & phrases: interpreting the uv-visible absorption spectra of photopigments of human eye, identifying the maximum absorption peaks in the uv-visible absorption spectra of photopigments of human eye, explaining the uv-visible absorption spectra of photopigments of human eye, how to use the visible absorption spectra of photopigments of human eye to explain the different colours of photopigments of human eye, applications of the uv-visible absorption spectra of photopigments of human eye uv-visible light absorption spectrum of red cones, identifying the maximum absorption peaks in the uv-visible absorption spectrum of red cones, explaining the uv-visible absorption spectrum of red cones, how to use the visible absorption spectra of red cones to explain the colour of red cones, applications of the uv-visible absorption spectrum of red cones uv-visible light absorption spectrum of blue cones, identifying the maximum absorption peaks in the uv-visible absorption spectrum of blue cones, explaining the uv-visible absorption spectrum of blue cones, how to use the visible absorption spectra of blue cones to explain the colour of blue cones, applications of the uv-visible absorption spectrum of blue cones uv-visible light absorption spectrum of green cones, identifying the maximum absorption peaks in the uv-visible absorption spectrum of green cones, explaining the uv-visible absorption spectrum of green cones, how to use the visible absorption spectra of green cones to explain the colour of green cones, applications of the uv-visible absorption spectrum of green cones uv-visible light absorption spectrum of photopigments of rods, identifying the maximum absorption peaks in the uv-visible absorption spectrum of photopigments of rods, explaining the uv-visible absorption spectrum of photopigments of rods, how to use the visible absorption spectra of photopigments of rods to explain the colour of photopigments of rods, applications of the uv-visible absorption spectrum of photopigments of rods


Associated links

UV and visible spectroscopy index

SPECTROSCOPY INDEXES

All Advanced Organic Chemistry Notes

Use My Google search site box

Website map buttons below

KS3 BIOLOGY QUIZZES ~US grades 6-8 KS3 CHEMISTRY QUIZZES ~US grades 6-8 KS3 PHYSICS QUIZZES ~US grades 6-8 HOMEPAGE of Doc Brown's Science Website EMAIL Doc Brown's Science Website
GCSE 9-1 BIOLOGY NOTES GCSE 9-1 CHEMISTRY NOTES and QUIZZES GCSE 9-1 PHYSICS NOTES GCSE 9-1 SCIENCES syllabus-specification help links for biology chemistry physics courses IGCSE & O Level SCIENCES syllabus-specification help links for biology chemistry physics courses
Advanced A/AS Level ORGANIC Chemistry Revision Notes US K12 ~grades 11-12 Advanced A/AS Level INORGANIC Chemistry Revision Notes US K12 ~grades 11-12 Advanced A/AS Level PHYSICAL-THEORETICAL Chemistry Revision Notes US K12 ~grades 11-12 Advanced A/AS Level CHEMISTRY syllabus-specificatio HELP LINKS of my site Doc Brown's Travel Pictures
Website content Dr Phil Brown 2000+. All copyrights reserved on revision notes, images, quizzes, worksheets etc. Copying of website material is NOT permitted. Exam revision summaries & references to science course specifications are unofficial.

 Doc Brown's Chemistry 

*

TOP OF PAGE