Ecosystems: Energy Flows and Trophic Levels

Energy Flows in Ecosystems

• Life on Earth depends on energy from the Sun.
• Energy from the Sun enters an ecosystem through photosynthesis, a process where plants, algae, and some bacteria convert sunlight into sugar molecules.
• These sugar molecules, or carbohydrates, are energy-rich molecules that organisms use to carry out daily activities.
• Energy is transferred from one organism to another as they consume food and use energy from carbohydrates.
• Producers, such as plants, algae, and some bacteria, are the first to receive energy from the Sun.
• Consumers depend on producers for energy, as they consume them to obtain energy.
• There are two main types of consumers:
• Energy transfer in a food web is more complex than in a food chain because it involves multiple pathways and interactions between organisms.
• An energy pyramid represents trophic levels, showing how energy is transferred from one level to the next, with the Sun as the primary source of energy.
• The energy pyramid illustrates the decrease in energy availability as you move from one trophic level to the next.