Seeds such as those of cereals and legumes have always been widely harvested to fuel the ever-growing demand of food and have also become a vital provider of the essential amino acids that cannot be produced by the human body, but are needed for growth and development. Classification of the proteins in vital seed based food sources by protein size, amount and solubility can help discover ways to improve seed composition and increase the nutritional content of seeds, thereby, reducing hunger and improving food production. In this experiment, we determine the proteins and their proportions in ground up rice, wheat and lentil seeds and compare solubility classes of these proteins. By determining the amino acid compositions from the results we would be able to suggest ways to improve plant seed based diets, using either GM or non-GM approaches, if the amino acids in the seeds are not sufficient to meet human requirements of essential amino acids. We found that rice grains contain the protein glutelin, wheat seeds contain prolamin and lentils contain globulins. Also the amino acids present in rice were sufficient to satisfy the human essential amino acid requirements as it provided almost all of the essential amino acids required by the human body.
Seeds are the main organs for dispersal and breeding in plants but are also the most widely harvested plant tissue that contributes to human survival. The protein content of seeds differ from about 10% of the dry weight in cereals to about 40% in some oilseeds and legumes, hence, becoming a major contributor of dietary protein. Seed proteins are of three types, housekeeping (or structural), storage and biologically active proteins. Housekeeping proteins help maintain normal cell metabolism while the biologically active proteins such as lectins, enzymes and enzyme inhibitors are small proteins which could have a nutritionally even amino acid arrangement as compared to storage proteins. Storage proteins are non-enzymatic and their main role is to provide proteins (nitrogen and sulphur source) needed for germination and creation of a new plant.
[...] Longmans Green: London pp. 21-28. Shewry, P.R., Napier, J.A. and Tatham, A.S. (1995) Seed storage proteins: structures 'and biosynthesis. The Plant Cell 945-956. Ufaz, S. and Galili, G. (2008) Improving the content of essential amino acids in crop plants: goals and opportunities. [...]
[...] However, in salt and alkali the wheat proteins were not soluble as observed by the lack of distinct bands for salt-1 and alk-1 wheat extracts. This would suggest that wheat seeds contain the protein prolamin, as only it is extracted using alcohol. Rice seed extracts contain a protein that is highly soluble in alkali and this is due to the distinct bands observed in well 7 (Figure 1 in Appendix I). However in salt and alcohol, rice proteins were not very soluble as observed by the lack of distinct bands for salt-1 and alc-1, although some small proteins were extracted by salt (salt-1). [...]
[...] Figure 1 SDS polyacrylamide gel image displaying bands produced for Group 14 wheat (wells and Group 15 rice (wells 5,6 and and Group 16 lentils (wells and 10) and the protein ladder (well 4). The molecular weights in kDa of the bands for the three rice extracts (group 15) are marked on the left hand side. A BLUeye prestained protein ladder reference, for monitoring protein separation in polyacrylamide gel electrophoresis, is shown on the right hand side for reference of the bands. Also a legend with descriptions of the extract solutions added into each well is provided under the image. [...]
[...] These would suggest that rice seed grains contain the protein glutelin, as it can only be extracted by alkali. The lentil extracts contained a protein that is highly soluble in salt and this is due to the numerous distinct bands observed in well 8 in Figure 1. However in alkali and alcohol, lentil proteins were not as soluble and this is observed from the lack of distinct bands for alc-1 and alk-1. These findings suggest that lentil seeds contain the protein globulin, as only it is extracted using salt. [...]
[...] Lentils contained globulin proteins as its solubility class was saline or salt solutions. The amino acid composition of rice was found to be sufficient in satisfying the human requirements of essential amino acids since more than 5 essential amino acids were present in rice grains. GM approaches to increase content of lysine, tryptophan and phenylalanine was suggested for rice seeds, as these amino acids were in small amounts and some were available. Bibliography Graham, P.H. and Vance, C.P. (2003) Legumes: Importance and constraints to greater use. [...]
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