Why do chlorophyll a and chlorophyll b have different Rf values? (Why is chlorophyll a slightly...
For TLC plate separation, why do we use Rf values instead of distance measurements (e.g. the spot travelled 5 cm from the starting line)? What would happen if we compared solvent systems using distances rather than Rf values?
slightly confused I thought Rf 0 was solid and Rf1 is slightly liquid please any help is greatly appreciated.3. Two extreme values for the Retention Factor are 0 and 1 a) Explain what each Re value means in terms of the substance's affinity for the mobile phase and for the stationary phase. b) Describe the features of molecules that would have these extreme Rr values under the conditions in this experiment: the solvent an 80:20 mix of petroleum ether and acetone, the...
1. If two spots have identical Rf values, does that mean that they are the same identical molecules? Explain why or why not. 2. What value is there in using at least two different solvent systems? How might this be related to question 1. 3. Do some research, and briefly describe the roles of each pigment group in a leaf. Chlorophylls, Carotenes and Anthrocyanins. If the exact function isn’t know, list several of the possibilities.
10.0 cm B carotene & Solvent Front 5.0 cm Xanthophyli Chlorophyll 3.0 cm Chlorophyll 10 cm B Leaf Material What is the Rf value for Xanthophyll ? 1 0.5 0.3 0.1
Why is there a direct correlation between the dielectric constant and the Rf value during a TLC analysis? What is the relationship between the solvent polarity and the Rf values? Why are some solvent mixtures better at separating compounds than others?
Why must Rf values be quoted along with the specific solvent system used for the TLC experiment concerned?
Differentiate between chlorophyll a and chlorophyll b. How are the two molecules structurally different and how do their absorption spectra differ?
1. Calculate the Rf values for spots A and B on the TLC plate drawn below. Based on the Rf values which compound (A or B) is most likely to be more polar? a. Calculate Rf values for A and B b. Which compound A or B will most likely be polar? Why?
Why do the phycobilins found in red algae trap more light energy than chlorophyll in deep water? Which of the green algae are motile? How do these organisms move? How are the pseudopodia of these amoebas different than the pseudopodia of Foramens and Radiolarians? Can you see any internal structures in the bacteria? Why or why not? Given the differences between bacterial and animal cells as previously discussesed, what aspects of abcterial structure might be good targets for antimicrobial agents?...
During a chromatography experiment, a student calculated two Rf values. They are A: .62 and B: ,30. The solvent front for the original chromatogram was 12.0 cm. If Aand B were run on a second chromatogram and the solvent front was 25.0 cm, how far apart would A be from B?