3. Energy Flow
In order to live out its life, an organism must obtain energy through some means
Sunlight is the main source of energy for life on Earth.

4. Autotrophs (Producers)
Autotrophs (producers) use energy from the sun to fuel to make organic molecules such as sugar; they make their own food
The best know autotrophs are those that harness the power of the sun through photosynthesis, plants. They use this energy to convert carbon dioxide and water into oxygen and glucose (sugar)
The second type of autotrophs use chemical energy to make carbohydrates. This is performed by several types of bacteria.

5. Heterotrophs (Consumers)
Heterotrophs (consumers) rely on other organisms for their energy and food.
Herbivores obtain energy by eating plants.
Carnivores eat animals.
Omnivores eat both plants and animals.
Scavengers feed on the remains of plants, animals and other dead matter.
Decomposers breaks down organic matter in environment

6. Energy Flow
Energy flows through an ecosystem in one direction, from the sun or inorganic compounds to autotrophs (producers) and then to various heterotrophs (consumers).

7. Energy Flow

8. Energy Flow

9. Food Chains and Webs
Food Chains are a series of steps in which organisms transfer energy by eating or being eaten; shows path of matter and energy
Food webs show the complex interactions within an ecosystem.
Energy transfer through the food chain is inefficient
This means that less energy is available at the herbivore trophic level than at the primary producer trophic level, less yet at the carnivore trophic level, and so on.
The result is a pyramid of energy, with important implications for understanding the quantity of life that can be supported.

10. Food Chains

11. Food Web

12. Ecological Pyramids
Each step in a food chain or web is called a trophic level. Producers make up the first step, consumers make up the higher levels.
Ecological Energy pyramid: a diagram that shows the relationship amounts of energy or matter contained within each trophic level in a food web or food chain.
only 10% of the energy available within one trophic level is transferred to organisms at the next trophic level.

13. Ecological Energy Pyramid

14. Ecological Energy Pyramid