Investigation: Vitamin A and Vision
Directions
Go to www.blackwellpublishing.com/matthews/rhodopsin.html Use the
visualization to guide you through the investigation. Answer the questions, as
completely as possible. If you do not know an answer, look it up.
1.Describe the first image of the visualization.
2. Where are rods located in the eye?
3. Draw rhodopsin. What is rhodopsin? Where is it located (be specific)?
4. What are isomers? What is photoisomerization?
5. What molecule is coupled to rhodopsin?
6. Draw an eye and indicate where the rods and cones are located. What types of rods
and cones do humans have? How are human eyes different than bird eyes? Give a
hypothesis as to what purpose the difference serves.
http://www.sas.upenn.edu/~ksundeen/spec%20project%20stuff/Eyes%20and%20Spect
rometers.html
7. Describe the outer segment of the rod. How is the human eye similar to a
spectrometer? (Hint:Can redraw “B” under How the human eye is like a spectrometer.)
8. Draw a rod. Label the outer, segment, inner segment, and nucleus. How are your 3
pictures different? http://en.wikipedia.org/wiki/File:Cone2.svg
9. How is vitamin A related to the mechanism shown in the online visualization?
10. What would happen in the prolonged deficiency of vitamin A in the body? Go to this
website to see other eye diseases and a simulation of what happens to eye sight:
http://www.nei.nih.gov/health/examples/
11. BONUS-Go to: http://www.3deyehealth.org/ Read the AOA report on 3D and
Vision. What are your thoughts? (For more info on the eye go to:
http://www.aoa.org/x6024.xml)