Chloroplast Essay

The high rate of absorbance change in blue light in the chloroplast samples (Figure 1) can be attributed to its short wavelength that provides a high potential energy. A high rate of absorbance change is also observed in red light in the chloroplast samples (Figure 1), which can be accredited to the reaction centre’s preference for a wavelength of 680nm and 700nm – both of which fall within the red light range (Halliwell, 1984). Green light showed low rates of photosynthetic activity and difference in change in absorbance at 605nm in the chloroplast samples (Figure 1) as it is only weakly absorbed by pigments, and is mostly reflected. The percentage of absorption of blue or red light by plant leaves is about 90%, in comparison to the 70–80% absorbance in green light (Terashima et al, 2009). Yet despite the high absorbance and photosynthetic activity of blue light, hypocotyl elongation was suppressed and biomass production was induced (Johkan et al, 2012), which is caused by the absorption of blue light by the accessory pigments that do not transfer the absorbed energy efficiently to the chlorophyll, instead direction some of the energy to other pathways. On the other hand, all of the red light is absorbed by chlorophyll and used efficiently, thus inducing hypocotyl elongation and the expansion in leaf area (Johkan et al, 2012).

The greater overall rate of absorbance change in all chloroplast samples (Figure 1) confirms role of chloroplasts’ in photosynthesis. However, the use of the supernatant sample as a negative control was expected to yield no activity, which was shown to be untrue (Figure 1) and is contributed to the contamination of the supernatant sample with chloroplast. The fragile envelope of the chloroplasts can be eas...

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... not limited to photoselective ones, with plant responses differing, even among cultivars of the same plant (Stamps, 2008). Because it is a relatively new technology concept, it requires further research to demonstrate and elucidate the effects of coloured shade nets. The above experiment is an example of the research that can be undertaken to confirm the effects of light colour on spinach beet cicla cultivation.

It can be concluded that chloroplast is responsible for photosynthesis, with blue light forming the highest rate of photosynthetic activity. The widespread use of coloured netting in the future could result in indoor plant growth that is unreliant on weather, and the ease of the production of crops with the desirable phenotypes. However, future research is still required to eradicate any unknown data and determine plant responses in relation to wavelength