why is starch production an indication that photosynthesis is occuring?
Photosynthesis is the process in which organisms convert carbon dioxide and water into oxygen and glucose. It requires light energy as well, which is absorbed by the chlorophyll. The water is absorbed through the roots of the plant and the carbon dioxide is absorbed through the leaves. Plants do not need to eat like humans need to, because they can produce their own food—glucose. The glucose is needed for cellular respiration, which occurs in the mitochondria.
Obviously, glucose production would be a sign that photosynthesis is occurring; however, starch is basically the storage version of glucose. Photosynthesis produces glucose, which can be immediately used or transported because it is a soluble sugar. The glucose can be converted into starch in order to be stored, because starch is insoluble. This means that it can not escape from the cells. The starch can be converted back to glucose as needed. Starch production is an indicator that photosynthesis is occurring because starch is created from the products of photosynthesis. If photosynthesis isn't occurring and producing glucose in the first place, starch production will not be occurring.
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