Often, the veins are still green after the tissues between them have almost completely changed color.Ĭhlorophyll is located in the thylakoid membrane of the chloroplast and it is composed of an apoprotein along with several ligands, the most important of which are chlorophylls a and b. During this time, the amount of chlorophyll in the leaf begins to decrease. As this cork layer develops, water and mineral intake into the leaf is reduced, slowly at first, and then more rapidly. In late summer, with daylight hours shortening and temperatures cooling, the veins that carry fluids into and out of the leaf are gradually closed off as a layer of special cork cells forms at the base of each leaf. During the growing season, however, the plant replenishes the chlorophyll so that the supply remains high and the leaves stay green. In their food-manufacturing process, the chlorophylls break down, thus are continually "used up". These sugars are the basis of the plant's nourishment – the sole source of the carbohydrates needed for growth and development. Ĭhlorophyll has a vital function: it captures solar rays and uses the resulting energy in the manufacture of the plant's food – simple sugars which are produced from water and carbon dioxide. Thus, the leaves of summer are characteristically green. When abundant in the leaf's cells, as during the growing season, the chlorophyll's green color dominates and masks out the colors of any other pigments that may be present in the leaf. Cross-section of a leaf showing color changesĪ green leaf is green because of the presence of a pigment known as chlorophyll, which is inside an organelle called a chloroplast.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |