Fig. 1 below shows a diagram of a chloroplast.
Fig. 1
Identify the parts of a chloroplast labelled A - C in Fig. 1.
The part of the chloroplast labelled B in Fig. 1 contains various photosynthetic pigments.
Suggest why chloroplasts contain more than one different photosynthetic pigment.
The pigments in a chloroplast can be separated and identified using a technique called thin-layer chromatography.
After extracting pigments from a spinach leaf, a student carried out thin-layer chromatography.
Some of their results can be seen in Fig. 2 below.
Fig. 2
Use the equation provided to calculate the Rf values for pigments X and Y in Fig. 2.
Table 1 contains value ranges for the Rf values of some common photosynthetic pigments.
Table 1
pigment | Rf value range |
carotene | 0.89 - 0.95 |
neoxanthin | 0.05 - 0.11 |
chlorophyll a | 0.64 - 0.69 |
chlorophyll b | 0.53 - 0.62 |
pheophytin a | 0.78 - 0.86 |
Use your answers to part (c) to identify pigments X and Y from Fig. 2.
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