Paper chromatography of Photosynthetic Pigments
Rf
the relationships of the distance moved by a pigment to the distance moved by the solvent front
How can pigments in plant cells be separated?
through paper chromatography
What is the purpose of the solvent?
to give a basis for calculating the different Rf values of pigments and separating them from each other.
Which are more soluble in the chromatography solvent, xanthophyll or chlorophyll a? explain.
xanthophyll, because it moved higher on the paper
What is the most important plant pigments in photosynthesis?
Chlorophylls: chlorophyll a & chlorophyll b
What is the basic importance of chromatography?
Chromatography allows for the separation of the components of a certain mixture, allowing for scientists to observes and generate results and ideas.
Chlorophyll a
a blue-green band of color
What is photosynthesis?
a process that plants, cyanobacteria and algae use to convert carbon dioxide (CO2) and water, in the presence of light energy, into carbohydrates (sugar)
Pigment
a substance that absorbs light
Chorophyll b
a yellow-green band of color
carotenes and xanthophylls (accessory pigments)
absorb light and transfer it to chlorophyll a
What is the rate of migration based on?
adsorption capacity of the chromatography paper and the solubility of the sample (i.e. solute) in the solvent.
How do you think that the Rf value is useful to scientists?
allows scientists to identify a pigment by comparing the Rf value to a known standard.
What does a small Rf value tell you about the characteristics of the moving molecules
That the solubility of the solution is low
Reactants in photosynthesis
Water, carbon dioxide, sunlight
Is it possible to have an Rf value greater than 1?
no, due to the solvent carry the pigment, the distance moved by the solvent will always be greater than the distance move by the pigment.
What greek words is "chromatography" derived from?
"chromo" and "graph"... which means "color writing"
Rf equation
(distance moved by pigment [solute])/(distance from pigment origin to solvent front)
Green pigments are essential for photosynthesis to take place. How do you think that a japanese maple tree, which only has red leaves, can carry out photosynthesis?
Although the leaves display a red color, chlorophyll is still contained inside the leaves; consequently, allowing for the tree to go through photosynthesis
What does D(unknown) signify?
Distance solute traveled
What does D(solvent) signify?
Distance solvent traveled
Why are photosynthetic pigments composed of more than one type of photosynthetic pigment?
Each pigment absorbs light efficiently differently regarding the electromagnetic spectrum; therefore, although chlorophyll a is the main pigment, the rest of them are crucial to the color production of the plant and how it partakes in photosynthesis.
Who invented chromatography and when?
Mikhail Tswett in 1910
Waste product of photosynthesis
Oxygen
Products of photosynthesis
Oxygen, Glucose, and water
What is the most important biological process on Earth/
Photosynthesis
If yellow xanthophyll were present in the extract, why did the extract appear green?
The abundance of green chlorophylls in the leaf extract is way more than any other color; therefore, the presence of other pigments is masked by the green.
What purpose does the chromatography paper have in this experiment?
The chromatography paper is a stationary factor that allows the solute and solvent to react and create results.
how is paper chromatography able to separate photosynthetic pigments into different colors?
The paper absorbs the mixture of pigments found in the spinach leaf and water solvent. and the capillarity of each pigment specifies how far each pigment moves up on the paper; consequently, separating the pigments.
As the solvent moves up the chromat strip by ______ action, substances in the mixture that are ________ in the solvent are carried along up the strip.
capillary; soluble
Green leaves contain:
chlorophyll a & b, carotenes, and xanthophylls
PaperChromatography
technique for separating dissolved compounds (such as chlorophylls, carotene, and xanthophyll) based upon their solubility in a solvent.
Photosynthesis happens in...
plants, algae, and some bacteria (autotrophs)
Chlorophylls a and b
primary photosynthetic pigments that absorb light for photosynthesis
Xanthophyll
yellow pigment
Carotene
yellow-orange pigment
Would you expect the Rf value of a pigment to change if we altered the composition of the solvent? Why or why not.
yes, because the pigments solubility would change if the composition of the solvent was altered.
