Energy Flow Section 3-2 Objectives: Trace the flow of energy as it decreases through the trophic levels from producers to the quaternary level. Contrasting autotrophs and heterotrophs Describing the niche of decomposers

Producers: Definition???? What is the main source of energy for life on Earth? What about organisms at the bottom of the ocean, where sunlight doesn’t reach? These organisms rely on energy stored in inorganic chemical compounds (i.e., salts).

Producers, continued… Producers are also called autotrophs. Some producers capture the energy from sunlight through a process called _________________. Photosynthesis uses light to convert ____________ and _____________ to ____________ and ______________.

Producers, continued… Photosynthesis Chemosynthesis “photo” = ?

Photosynthesis vs. Chemosynthesis 6CO2 + 6H2O → C6H12O6 + 6O2 Carbon dioxide + water yields carbohydrates (glucose) and oxygen, in the presence of sunlight. Chemosynthesis: Hydrogen sulfide and oxygen combine to form sulfur compounds, which are then used with carbon dioxide to make carbohydrates. What do sulfur compounds smell like?

Consumers: What are they?? AKA, heterotrophs: Types of heterotrophs (consumers): Herbivores Carnivores Omnivores Detritivores Decomposers

Feeding Relationships Where does the energy flow begin in an ecosystem? ANSWER: sunlight or inorganic chemical compounds Then it flows in one direction, from producers to various levels of consumers (heterotrophs).

Food Chains: Def: a series of steps by which organisms transfer energy by eating or being eaten. http://ejad.best.vwh.net/java/population/facts_foodchain.html

Food Webs: Def: a network of complex interactions of all the food chains in an ecosystem.

Trophic Levels Producers Primary consumers (herbivores) Secondary consumers (carnivores which eat herbivores) Tertiary consumers (carnivores which eat other carnivores) Apex predators – carnivores which have no predators

Ecological Pyramids