How Energy Flows Through a Food Chain
- It starts with the producers: Plants, algae, and some bacteria capture sunlight through photosynthesis, converting it into chemical energy stored in carbohydrates.
- Then, the primary Consumers: Herbivores, like zebras, eat plants and absorb this energy.
- The Secondary Consumers: Carnivores, like lions, eat herbivores and gain energy from their tissues.
- Finally, the tertiary Consumers: Apex predators, such as eagles, consume secondary consumers.
- Energy flows through ecosystems, while matter cycles.
- This means energy is not recycled—it enters as sunlight and leaves as heat.
This is why ecosystems have many more plants than herbivores, and fewer predators than prey.
Why Energy Cannot Be Recycled
- Energy Dissipates as Heat: During respiration, chemical energy is converted to ATP, but much is lost as heat, which cannot be reused by organisms.
- Matter, Unlike Energy, Cycles: Elements like carbon and nitrogen are recycled through decomposition and nutrient cycles, but energy flows in one direction, from the sun to space.
Energy flows one way, while nutrients are recycled.
The Role of Decomposers
- Breaking Down Organic Matter: Decomposers like fungi and bacteria break down dead organisms, releasing nutrients back into the ecosystem.
