Yhteyttämisprosessi

Yhteyttämisprosessi, known in English as photosynthesis, is the fundamental biological process by which green plants, algae, and some bacteria convert light energy into chemical energy. This stored chemical energy is then used to fuel the organism's metabolic activities. The process primarily takes place in specialized organelles called chloroplasts, which contain chlorophyll, the pigment that absorbs sunlight.

During photosynthesis, carbon dioxide from the atmosphere and water absorbed from the soil are the main raw materials. Light energy, captured by chlorophyll, drives a series of chemical reactions. These reactions split water molecules, releasing oxygen as a byproduct into the atmosphere, and combine the hydrogen atoms with carbon dioxide to form glucose, a simple sugar. Glucose serves as the primary source of energy for the organism and can be further converted into other organic compounds necessary for growth and development.

The overall equation for photosynthesis is often summarized as 6CO2 + 6H2O + Light Energy → C6H12O6 + 6O2. This process is vital not only for the producers themselves but also for virtually all life on Earth, as it forms the base of most food chains and is responsible for replenishing the atmospheric oxygen consumed by respiration. Variations in photosynthetic pathways exist, such as C3, C4, and CAM photosynthesis, which are adaptations to different environmental conditions, particularly regarding water availability and temperature.