1. Recall that carotene and xanthophyll have very similar molecular structures e
ID: 201694 • Letter: 1
Question
1. Recall that carotene and xanthophyll have very similar molecular structures except for the presence of two hydroxide groups in xanthophyll. Use this information to explain the difference in Rf values for these two pigments given the substrate/solvent combination employed in this exercise.
2. Given your understanding of how deciduous trees behave in autumn, which of these pigments tends to be retained the longest before leaves fall? How do you expect photosynthesis rates to change during this time? Explain your answer by employing your observations from both of the exercises in lab this week
Explanation / Answer
Ans.) Plants have different kinds of pigments which are produced by the organelles called chloroplast present in the leaves. Chlorophyll is the major pigment that basically absorbs yellow and blue colors and thus emit the traditional green color which is the characteristic common in all the plants. Other than that, there are other pigments like carotenoids that emit red, orange or yellow color and xanthophyll which emits the yellow one etc. These two have very similar molecular structure but the xanthophyll contains oxygen atoms in a hydroxyl group whereas the carotene are purely hydrocarbons with no oxygen.
Rf value is basically the ratio of distance moved by solute and that moved by the solvent along the paper used to differentiate the different elements of the pigments. As the solvent moves up the plate, chemicals in the mixture move up with it at different rates, so they tend to separate.
Related Questions
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.