Food For Thought – Energy

Energy Capacity to perform work Kinetic energy = motion Potential energy = stored energy

Energy is always conserved It cannot be created nor destroyed Available in different forms Light energy Heat energy Chemical energy Mechanical energy

Energy is always conserved It can not be created or destroyed Can be converted from one form to another Ex: gasoline  movement and heat

When converting energy, some is always ‘lost’ as heat Solar energy hitting earth daily = energy of 100 million atomic bombs Less than 1% is converted to chemical energy by photosynthesis

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

How do we get our energy?

Producers Green Plants Capture light energy from the sun and convert it into food energy.

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

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

Consumers = Heterotrophs Producers = Autotrophs

Respiration?

Converting energy in living organisms Photosynthesis and Respiration

ATP (Adenosine Triphosphate) The form of energy used by cells for cell activities Energy 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 It takes energy to make ATP Breaking down ATP releases energy

ATP (Adenosine Triphosphate) All organisms get their ENERGY from ATP. Without ATP all living organisms will DIE.

Photosynthesis & Respiration PHOTOSYNTHESIS Production Harvests sunlight energy Converts to chemical energy Stores energy in form of organic molecules (glucose) RESPIRATION Consumption Breaks down organic molecules into chemical energy

Photosynthesis and Respiration Form a Cycle

Photosynthesis Converts light energy into chemical energy (ATP, NADPH) Chemical energy and CO 2 made into sugars Requires H 2 O, CO 2, and sunlight

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

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

Factors affecting Photosynthesis Amount of LIGHT Intensity of the LIGHT Amount of WATER DIRECTION of the light Temperature

Fuel OxygenHeat

Respiration The 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

Types of Consumers Primary Consumer (Herbivores) – eat PLANTS to get energy Secondary Consumers (Carnivores, omnivores) – eat ANIMALS to get energy Tertiary Consumers (Carnivores, omnivores) – eat ANIMALS to get energy

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

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

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

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

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

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