Brand New Lab. 10th Grade. Photosynthetic pigments.

Thin layer chromatography is used to separate components of a plant extract, illustrating the experiment with plant pigments that gave chromatography its name

Hey there. This lab is the newest one and we've never done before. So, enjoy!

Title: Chromatography. Pigments separation method.

Background: By extracting pigments from leaves and placing these samples into a chromatography machine, scientists can identify which wavelengths of light an organism can absorb. Methods for the identification of plant pigments include various types of chromatography that separate the pigments by their relative affinities to solid and mobile phases.

Chlorophyll a, chlorophyll b, and β-carotene are hydrophobic organic pigments found in the thylakoid membrane. Chlorophyll a and b, which are identical except for the part indicated in the red box, are responsible for the green colour of leaves. β-carotene is responsible for the orange colour in carrots. Each pigment has a unique absorbance spectrum. Chlorophyll a absorbs wavelengths from either end of the visible spectrum (blue and red), but not green. Because green is reflected or transmitted, chlorophyll appears green. Carotenoids absorb in the short-wavelength blue region, and reflect the longer yellow, red, and orange wavelengths. The carotenoids found in fruit—such as the red of tomato (lycopene), the yellow of corn seeds (zeaxanthin), or the orange of an orange peel (β-carotene)—are used as advertisements to attract insects and birds. In photosynthesis, carotenoids function as photosynthetic pigments that are very efficient molecules for the getting rid of excess energy. When a leaf is exposed to full sun, the light-dependent reactions are required to process an enormous amount of energy; if that energy is not handled properly, it can do significant damage. Therefore, many carotenoids reside in the thylakoid membrane, absorb excess energy, and safely cause to disappear that energy as heat.

Purpose: To identify pigments of green leaves of the plant.

Equipment: 

Procedure: You write it using the file (Simple chromatography technique. Download this file before writing the procedure. It is in Russian) in English.

Result:

Conclusion:

Use the SAMPLE LAB WORK REPORT for the best grade!