Energy flow
| English | Chinese | Pinyin |
|---|---|---|
| producers | 生产者 | shēng chǎn zhě |
| photosynthesis | 光合作用 | guāng hé zuò yòng |
| food chain | 食物链 | shí wù liàn |
| consumers | 消费者 | xiāo fèi zhě |
Where all the energy comes from
- Almost all the energy in living things can be traced back to one source: the Sun.
- Following that energy through an ecosystem is the heart of ecology.
The original source of energy for almost all ecosystems is the:
Producers capture the Sun's energy.
Producers 生产者 capture the energy
- Producers (green plants) capture light energy by photosynthesis 光合作用.
- They turn it into chemical energy stored in glucose — the food that feeds everything else.

A food chain 食物链: arrows show energy passing from producer to consumers 消费者
Energy flow through a food chain
Energy from the Sun enters living things through plants, then passes along the food chain — losing a lot at each step.
Producers capture energy by:
Green plants photosynthesise to store energy.
Green plants that make their own food and start a food chain are called ______.
Producers are the first link in a food chain.
Energy passes on
- Consumers get their energy by eating producers or other consumers.
- Energy flows from the Sun → producers → consumers along a food chain.

A savanna ecosystem: organisms linked by feeding relationships
Energy is lost between stages of a food chain mainly as:
Respiration, movement and waste lose energy as heat.
Energy flows through an ecosystem and is lost, rather than being recycled.
Energy must be resupplied by the Sun; only nutrients cycle.
Energy is lost at each step
- At every stage, energy is lost as heat (from respiration), movement and waste.
- So less energy is available the further along the chain you go.
Energy flows; it doesn't cycle. Unlike nutrients (carbon, nitrogen), energy is lost at each step and must be constantly resupplied by the Sun. It is not recycled.
You've got it
- nearly all energy comes from the Sun, captured by producers (photosynthesis)
- consumers get energy by eating; energy flows Sun → producers → consumers
- energy is lost at each step (heat, movement, waste) — it flows, it doesn't cycle