Photosynthesis:
Plants require water from the soil, sunlight and carbon dioxide found in the atmosphere for growth and development. In the process of photosynthesis, carbon dioxide and water – in the presence of chlorophyll and light energy – are converted into sugar and oxygen, which is given off as a by-product. Generally, as sunlight increases in intensity, the rate of photosynthesis also increases [1]. This means greater food production within the plant. Many garden vegetables, like tomatoes, respond best with maximum sunlight exposure. Production is drastically cut when plants are grown in the shade; this is because the rate of photosynthesis in the plant has been drastically reduced [4].
Photosynthesis is the process in which the photoautotrophs (plants that use light energy) convert sunlight energy into chemical energy and stores it in the form of ATP. Photosynthesis begins with the carbon dioxide in the atmosphere when it enters the stomates; tiny epidermal pores that lie within the leaves and stem of a plant that assist the process of transferring various passes and water vapours. This is followed by water entering the leaf, usually through the roots, which were created to draw water from the ground, and transport waters through the stem to the leaves [6]. The sunlight then shines onto the leaves, the present chlorophyll’s from the leaves trap the energy from the sunlight. Chlorophyll present in the leaves create the green colour on the leaves; it also helps the plant absorb all sunlight, except the colour green which it reflects. The hydrogen and oxygen are then produced as the products of photosynthesis; the hydrogen is then combined with carbon oxide to create glucose for the plant, while the oxygen is let out through the stomates on the leaves [5]. The chemical reaction within the cell between the electrons from the chlorophyll molecules and the protons from the water molecules produce ATP (adenosine triphosphate), which
References: 1. Campbell, N (1999) Biology, Benjamin-Cummings Publ. Co., California [http://biology.clc.uc.edu/courses/bio104/photosyn.htm] 2. Davidson, S. (2007) Electromagnetic Radiation, Maricopia Education, New York, http://www.nationalelectrical.com/clncmpd.htm [13/03/2010] 3. Eates, P. J. (2004) Electromagnetic Spectrum, The Share Guide, Sydney, [http://www.lbl.gov/] 4. Farabee, M (2007) Photosynthesis and Light, Maricopia Education, New York [http://www.emc.maricopa.edu/faculty/farabee/biobk/biobookps.htmlhttp://www.emc.maricopa.edu/faculty/farabee/biobk/biobookps.html] 5. Marchuk, W. (1992) A Life Science, Brown Publishers, Iowa. [http://www-saps.plantsci.cam.ac.uk/articles/broad_light.htm] 6. Reece, J. (2001) Biology: Concepts and Connections, Benjamin-Cummings Publ. Co., California [http://www.ftexploring.com/photosyn/photosynth.html] 7. Purves, F (2000) Effect of Coloured Light on rate of Photosynthesis, Macquarie Educational Publishings, Melbourne [http://library.thinkquest.org/3715/photo3.html]