Photosynthesis

Name:
Photosynthesis
Detailed information:
The utilization of sunlight by plants and bacteria to convert two inorganic substances (carbon dioxide and water) into carbohydrates. Chlorophyll acts as the energy converter in this reaction, which is perhaps the most important on earth. The generalized reaction is 6CO₂ + 6H₂O + 672 kcal → C₆H₁₂O₆ + 6O₂. The significance of this process lies in the conversion of energy from radiant to chemical form. The chemical energy that a green plant stores by photosynthesis provides the total energy requirement of the plant. Directly or indirectly plants supply the primary organic nutrient for most other living organisms. Most fossil fuels are storehouses of the radiant energy transformed by photosynthesis in earlier geologic eras.Photosynthesis is the principal source of atmospheric oxygen. At least two-thirds of the total photosynthetic activity of the earth takes place in the oceans. Its exact chemical mechanism is extremely complex. Essential features are the reduction of carbon dioxide and the utilization of the hydrogen of water to form carbohydrates, with oxygen being liberated; the nucleotides nicotinamide and adenosine triphosphate are involved in this conversion. Sugar (sucrose) is formed in the cytoplasm surrounding the chloroplasts. Photosynthesis has been shown to be substantially inhibited by air pollution to the extent of 20% in rural locations and 33% in urban areas.See Algae.