Understanding:
• Most ecosystems rely on a supply of energy from sunlight
• Light energy is converted to chemical energy in carbon compounds by photosynthesis
All green plants, and some bacteria, are photoautotrophic – they use sunlight as a source of energy
- This makes light the initial source of energy for almost all communities
- In a few ecosystems the producers are chemoautotrophic bacteria, which use energy derived from chemical processes
Light energy is absorbed by photoautotrophs and is converted into chemical energy via photosynthesis
- This light energy is used to make organic compounds (e.g. sugars) from inorganic sources (e.g. CO2)
- Heterotrophs ingest these organic compounds in order to derive their chemical energy (ATP)
- When organic compounds are broken down via cell respiration, ATP is produced to fuel metabolic processes
Overview of Photosynthesis
