Food For Thought – Energy

Ecology zthe study of the RELATIONSHIPS of living things to EACH OTHER and their ENVIRONMENT (surroundings)

Ecosystems zALL of the LIVING communities of an area together with the NON-LIVING parts of their ENVIRONMENT

Parts of an Ecosystem zLIVING community (BIOTIC factors) zENERGY input and use zNUTRIENT cycling zNON-LIVING environment (ABIOTIC factors)

Ecology involves the study of the following things: zThe interactions between members of the BIOTIC community (the living plants, animals and microbes) zThe interactions between members of the BIOTIC community and the NON- LIVING environment zThe interactions between the ABIOTIC environmental factors (such as light- temperature-moisture)

The Environment and Energy zEnergy – the ABILITY to do WORK zAll LVING ORGANISMS use energy for life processes.

Forms of Energy: z1. Light z2. Heat z3. Chemical z4. Mechanical z5. Electrical

First Law of Thermodynamics zEnergy is never CREATED nor DESTROYED but is only CHANGED from one form to another, or TRANSFERRED from one place to another.

Second Law of Thermodynamics zWhen ENERGY is transformed or transferred, a part of the energy is LOST in the form of HEAT.

How organisms obtain energy zECOSYSTEMS are powered by energy from the SUN zEnergy only enters living things at the PRODUCER level. zAs energy is passed along the FOOD chain, much of it is lost as HEAT.

How organisms obtain energy zEnergy flows ONE way through the food chain, from PRODUCERS through CONSUMERS. zEach level of the food chain has LESS available energy in it.

Different organisms get energy in different ways zAutotroph -- organisms that can make their own food (green plants) zHeterotrophs -- organisms that cannot make their own food and have to feed on autotrophs or other heterotrophs (cows)

ATP (Adenosine Triphosphate) zThe form of energy used by cells for cell activities zEnergy stored in ATP is BROKEN DOWN by ATPase, an ENZYME, to a molecule of ADP. When that chemical bond is broken, energy is released.

ATP (Adenosine Triphosphate) zWithout ATP all living organisms will DIE. zAll organisms get their ENERGY from ATP.

Photosynthesis 6CO 2 + 6H 2 O > C 6 H 12 O 6 + O 2 CARBON +WATER SUNLIGHT SUGAR + OXYGEN DIOXIDE

Three Phases zLight absorption by CHLOROPHYLL zLight Dependent reactions – water is SPLIT into HYDROGEN and OXYGEN. OXYGEN is released and energy is transferred to the next phase. zLight Independent reactions – carbon dioxide and WATER are combined to form CARBOHYDRATES

Factors affecting Photosynthesis zAmount of LIGHT zIntensity of the LIGHT zAmount of WATER zDIRECTION of the light zTemperature

Respiration zThe release of energy from sugar molecules C 6 H 12 O 6 + O > 6CO 2 + 6H 2 O SUGAR + OXYGEN ENZYMES CARBON +WATER DIOXIDE

How They Fit in Trophic Levels

Producers zGreen Plants zThey capture light energy from the sun and convert it into food energy.

Consumers zare Animals that depend upon green plants and other animals for food.

Types of Consumers zPrimary Consumer (Herbivores) – eat PLANTS to get energy zSecondary Consumers (Carnivores, omnivores) – eat ANIMALS, to get energy zTertiary Consumers (Carnivores, omnivores) – eat ANIMALS, and Plants to get energy

Decomposers zBreak down and DECOMPOSE DEAD ORGANISMS getting energy and releasing nutrients back into the environment.

You Are What You Eat zFood Chains – a simple LINEAR drawing showing which organisms feed upon which others

You Are What You Eat z Food Web – A NUMBER OF INTER- CONNECTING FOOD CHAINS

Pyramids of Numbers zNumbers decrease as we go from one food level to the next. Numbers that decrease are BIOMASS, AVAILABLE ENERGY, and organism population size.

Soils