What pigments are present in the Northern Red Oak ?

— Have you ever woken up thinking about photosynthesis ??
—I know right? me too  🙂

Today I woke up with an odd feeling to learn more about plant pigments ^^;
Let’s remember the basics:

“Photosynthesis in plants takes place in organelles called chloroplasts. Chloroplasts contain a number of colored compounds (pigments) which fall into two categories, chlorophylls and caretenoids.”

The beauty about biology is that it allows you to reflect upon life in general (plants, animals, humans) and through experiments, we are able to date and learn about historical and current specimens on an absolute timescale.

By using column chromatography we are going to see the isolation of plant pigments from the Northen Red Oak.

According to the naturalist Joseph S. Illick, the Northern Red Oak  (Quercus rubra) has been called “one of the most handsome cleanest, and stateliest trees in North America.” it is widely considered a national treasure; it is highly valued in urban settings due to its brilliant fall color and status as the state tree of New Jersey.

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Vocabulary:

Chromatography:  Laboratory technique for separating components.

Chlorophyll: The molecule that absorbs sunlight and uses its energy to synthesize carbohydrates.

Carotenoids: Plant pigments responsible for bright red, yellow and orange hues…  Carotenoids are a class of phytonutrients (“plant chemicals”).

Experiment:

The oak leaves’  chlorophyll and carotenoids pigments were extracted and separated.
The video shows the process of column chromatography to separate the different pigments. Column chromatography works by separating solutes of different polarity. The colored fractions collected will then be used to elute the various components from the column.

 

 

 

The test tube image shows the different fractions of pigments that were separated from the extract by column chromatography.

Test Tube

Now we will determine what pigments are present:
The next picture is TLC (thin layer chromatography) plates.
The top yellow pigment on the plates are carotenes, then the next gray mark is pheophytin, followed by the dark green is chlorophyll a, light green is chlorophyll b,  the lower, lighter yellow spot is xanthophylls.

TLC

So now we know what pigments are present in the Northern Red Oak.
But did you know that all of it is present in our daily diets and the life of plants?

Here is a small explanation of what the results from above mean:

Carotene: The red and orange pigments of many plants, obvious in carrots, red palm oil, and yellow maize. These are important producers of vitamin A and, they are antioxidant nutrients; there is evidence that they provide protection against ischaemic heart disease. 

Pheophytin: It is a chemical compound that serves as the first electron carrier intermediate in the electron transfer of Photosystem II in plants.

Chlorophyll a: It absorbs most energy from wavelengths and contributes to the green color of most of the plants.

Chlorophyll b: It is a yellow-green pigment mostly found in plants and green algae.

Xanthophylls: Type of plant pigment that acts as the metabolism of plants and serves as a protection against excessive sunlight.

If you made it this far, I hope you learn something new about plants 🙂

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