4.6 Energy and Substances in Food Chains

Bush Grass = Producer
Impala = Primary Consumer
Leopard = Secondary Consumer
Lion = Tertiary Consumer

- Producer: converts light energy into chemical energy. The chemical energy takes the form of organic molecules including: carbohydrates, proteins and lipids. These molecules, which are called food, are composed of:
C-H
C-O
C-C
O-H
C-N
bonds.
- These bonds all represent energy
- Carbon, Hydrogen, Nitrogen and Oxygen are the substances/matter

- As bush grass carries out photosynthesis it creates the organic molecules which are the substances and contain the energy which was fixed from sunlight, now in the form of chemical energy.
- The impala consumes this for: respiration, growth and life processes
- When the leopard eats the impala, these molecules are passed on and re-organized into leopard form, and so on...

Substances/Matter and the energy which is in the bonds between the elements are passed from each stage in the food chain.

4.4 Trophic Levels

- Tropic = feed
- In the example:

• the carrot plant is doing the photosynthesis - - - - - in ecology terms - - - - - Producer (light energy and turning it into chemical energy)
• the carrot fly is eating the plant = herbivore - - - - - in ecology terms - - - - - Primary Consumer (chemical energy of the plant into chemical energy of the fly - change in the form of the chemical energy)
• the flycatcher eats the fly = carnivore - - - - - in ecology terms - - - - - Secondary Consumer (again, changing the chemical energy from one form to another)
• another carnivore eating another carnivore = top carnivore. - - - - - in ecology terms - - - - - Tertiary Consumer (Chemical energy from one form to another)

At some stage, they all die.

At this point, decomposers break the complex molecules down into nitrates and phosphates. 

fungi and bacteria are an example of decomposers.