Chapter 3.2 Energy Flow

Producers Autotroph-organism that can capture energy from sunlight or chemicals and use it to produce its own food from inorganic compounds; also called a producer. All plants and some microorganisms make their own food from sunlight. Producer- organism that can capture energy from sunlight or chemicals and use it to produce food from inorganic compounds; also called an autotroph.

Producers: ENERGY FROM THE SUN Photosynthesis- process by which plants and some other organisms use light energy to power chemical reactions that convert water and carbon dioxide into oxygen and high-energy carbohydrates such as sugars and starches.

Producers: Photosynthesis

Producers: ENERGY WITHOUT LIGHT Chemosynthesis-process by which some organisms use chemical energy to produce carbohydrates

Different feeding levels Producers (autotroph) Consumers (heterotroph) Herbivore Carnivore Omnivore Detrivotore Decomposers

CONSUMERS Heterotroph- organism that obtains energy from the foods it consumes; also called a consumer Consumer- organism that relies on other organism for its energy and food supply; also called a heterotroph Detrivotore- organism that feeds on plant and animal remains and other dead matter. Ex: mites, earthworms, snails, and crabs Decomposer-organism that breaks down and obtains energy from dead organic matter. Ex. bacteria and fungi

Consumers: 3 Kinds of common heterotrophs Herbivore- organism that obtains energy by eating only plants. Ex: cows, caterpillars, deers. Carnivore- organism that obtains energy from eating animals. Ex: snakes, dogs and owls. Omnivore-organism that obtains energy by eating both plants and animals. Ex: humans, bears and crows.

FEEDING RELATIONSHIP: energy flows through an ecosystem in one direction, from the sun or inorganic compounds to autotrophs (producers) and then to various heterotrophs (consumers). -3rd level consumer- omnivore -2nd level consumer- carnivore -1st level consumer- herbivore -producer- plants

Food web examples

FOOD CHAINS: Food chain -series of steps in an ecosystem in which organisms transfer energy by eating and being eaten Food web-network of complex interactions formed by the feeding relationship among the various organisms in an ecosystem. Trophic level-step in a food chain or food web. Producers make up the first trophic level. Consumers make up the second, third and fourth level.

ECOLOGICAL PYRAMIDS There are 3 ecological pyramids: 1. ENERGY PYRAMID Ecological pyramid- diagram that shows the relative amounts of energy or matter within each trophic level in a food chain or food web Only 10% of energy available in one trophic level is transferred to organisms at the next trophic level.

ECOLOGICAL PYRAMIDS 2. BIOMASS PYRAMID Biomass- total amount of living tissue within a given trophic level 3. PYRAMID OF NUMBERS Pyramid of numbers: is based on the numbers of individual organisms at each trophic level.

Vocabulary phot – or photo – light chem.- or chemo – chemistry synthesis – production of substance herb- plant carn-meat omni – all detritus – organic particles vore - eat

QUESTIIONS: What are the two main forms of energy that power living things? 1. Solar energy (the sun) is obtained by autotrophs in the process of photosynthesis (plants/algae) 2. Chemical energy is obtained by autotrophs in the process of chemosynthesis (bacteria/microorganisms)

Briefly describe the flow energy among organisms in an ecosystem. There is one-way energy flow in the system. First energy starts from autotrophs (producers) and moves up to heterotrophs (consumers), first herbivores, carnivores, and then omnivores.

What proportion of energy is transferred from one trophic level to the next in an ecosystem? In general, about 10%

Show the following as food chain: omnivore, autotroph and herbivore. Autotroph-> herbivore-> omnivore

Critical thinking: Calculating: Draw an energy pyramid for a five-step food chain. If 100% of the energy is available at the first trophic level, what % of the total energy is available at the highest trophic level? At the first level (producers) 100% energy Second level 10% energy Third level 1% Fourth level 0.1% Fifth level 0.01%