Food chains (2)

• Begins with the Sun’s energy• Solar/radiant energy converted to

chemical energy by primary producers

• Amount of available energy decreases from trophic level to trophic level (most energy at trophic level 1 – primary producers, least energy at trophic level 5 – quaternary consumers

Food Webs• Arrows show the direction the energy is

flowing• Number of organisms (amount of

biomass) and amount of available energy typically decreases from trophic level to trophic level (ex: there will be fewer quaternary consumers than tertiary consumers because the amount of energy available decreases as the levels go up)

• Analysis: • how many?

(primary/secondary/tertiary/quaternary consumers are there)

• What’s missing?• Who gets energy from who?• What happens if? (something is removed)

Energy Pyramids• Quantifies energy transfer by

showing how much energy moves from trophic level to trophic level• Maximum amount of energy,

number of organisms and biomass at trophic level 1• 10% Rule • Analysis:

• Most/least energy? • Most/least biomass? • Greatest/least number of

organisms? • How much energy at each

level?

Primary Producers

Primary Consumers

Secondary Consumers

Tertiary Consumers

Quaternary Consumers

Photosynthesis• Plants, algae and phytoplankton can

photosynthesize• Takes place in the chloroplast• Converts radiant energy to chemical

energy (stored in the bonds of the glucose molecules)

Cellular Respiration• Cellular respiration occurs in

all organisms (plants and animals)• Takes place in the

mitochondria• Releases energy from glucose

molecules• Converts chemical energy to

mechanical, thermal, electrical etc

Nitrogen Cycle

Carbon Cycle• Photosynthesis, cellular

respiration and decomposition are all integral processes in the natural carbon cycle• Photosynthesis (uses

CO2 to make its own food), cellular respiration (releases CO2 to the atmosphere) and decomposition (releases CO2 to the atmosphere and the soil)

• Closely related to Global Warming

Decomposition• Matter is neither

created nor destroyed• Needs to be recycled• Decomposition

restores elements needed to produce organic compounds to the ecosystem• Decomposition

releases energy from the biomass back into the ecosystem

Composting• Process of creating ideal conditions

for speeding up natural decomposition• Composting requires the following:• Organic waste • Soil bacteria• Water • Oxygen from the air

• Composting produces the following:• Carbon Dioxide• Heat• Humus (finished compost)