Why is it that only 10% of energy is passed through a food chain? In this IBDP Biology post, we will see how energy is lost in different ways.
Reasons for Energy Loss
Cell Respiration
- Organisms release energy from carbon molecules to be used for muscle contration or active transport
- Energy which is converted into heat energy is lost
- Heat energy
cannot be converted back into chemical energy which is why
- Heat is lost from the ecosystem
- An energy source is required to replace the energy lost [sunlight]
Food passed to Saprotrophs rather than the next Trophic Level
- Organisms die before eaten [disease]
- Parts of organisms cannot be eaten [hair, bones]
- Indigestible parts [cellulose]
Energy Lost because of Energy Transfer
In IBDP Biology, we learn that energy stored in organic molecules can be transferred by cell respiration to ATP
ATP is used by cells to support their metabolism:
- Building
and breaking molecules
- Homeostasis
- Growth
Heat energy is also produced but is wasted
Ineffiencies in Energy Transfer
- Toxic organic molecules are excreted
- Ingested material is not absorbed and is egested
- Parts of an organism remain uneaten [fibres from plants and bones from animals]
Heat is lost from Ecosystems
Heat cannot be converted back into chemical energy so it is lost from the ecosystem
Solution: Energy source to replace the lost energy - Sunlight
Thermal energy released from the organism dissipates and is eventually lost from the ecosystem
Contrary to light and chemical energy heat energy cannot be converted into forms that is useful for the organism
Ecosystems require a continuous source of light to survive
Useful energy transfers from chemical energy for the organism
- Kinetic Energy - Muscle Contractions
- Electrical Energy - Nerve Impulses
- Light Energy - Bioluminscense
- Chemical Energy - Anabolism
- Heat Energy - Body Temperature in Endotherms
That is all!! Good job!
Drafted by Venetia (Biology)