Coloured Cellophanes Effects On Photosynthesis

3583 Words15 Pages
Coloured Cellophanes effects on Photosynthesis Background Theory: For photosynthesis to take place a plant requires carbon dioxide, water, light, chlorophyll and a suitable temperature. The necessity of these factors can be demonstrated by simple experiments either on whole plants or leaves (Moment, Habermann 1973). Autotrophs are organisms capable of making their own food. Autotrophs are also called producers because they can use the energy in sunlight or chemicals to produce food. The process of photosynthesis is when plants use the energy in sunlight to convert water and carbon dioxide into oxygen and high-energy carbohydrates. Photosynthesis occurs inside a cell organelle called the chloroplast. The chloroplast contains green pigments called chlorophyll, which capture the energy in sunlight. The equation for photosynthesis is as follows: Light 6CO2 + 6H2O à C6H12O6 + 6O2 (Moran 2006) The raw materials needed for photosynthesis are carbon dioxide from the air (taken in through the leaves) and water, usually from the soil (taken in through the roots). The two combine initially to produce simple sugars and oxygen. As seen in the above equation, sunlight is the energy source, and the green pigment chlorophyll is the means whereby the sunlight can be used. In biochemical terms, the whole process is the reduction of carbon dioxide (to simple sugars) by hydrogen obtained from the breakdown of water mediated by chlorophyll. (The Plant World 2000) Chlorophyll is a green pigment which absorbs all wavelengths of light except green, as it reflects it to be detected by our eyes. It traps the light energy so that the process of photosynthesis can occur (May 2001). To tell which colours of light are most absorbed and used by plants an action spectrum can be used. A picture of the spectrum is as below; if you read along
Open Document