POWER FOR LIFE’S PROCESSES Energy Flow

Producers Sunlight is the primary source of energy source for life on earth. Plants, algae, and some bacteria harness sunlight or chemicals to produce food. “Autotrophs” – make complex organic molecules from simple inorganic compounds using energy from the environment  Organic molecules are used to make living tissues Also called “Producers”

Producers Energy from the Sun  Photosynthesis  Using energy from sun to make carbohydrates  Water and carbon dioxide  carbohydrates and oxygen  Primarily plants (on land)  Algae and Cyanobacteria (in oceans) Life Without Light  Chemosynthesis – making carbohydrates using chemical energy (no sun)  Bacteria Live in volcanic vents on the ocean floor, hot springs, and tidal marshes

Consumers Organisms that obtain energy from other organisms Animals, fungi, and many bacteria “Heterotrophs” or “Consumers” Kinds:  Herbivores – eat plants  Carnivores – eat animals  Omnivores – eat plants AND animals  Detritivores – eat dead matter  Decomposers – break down organic matter

Feeding Relationships Energy flows through an ecosystem in one direction, from the sun or inorganic compounds to autotrophs (producers) and then to various heterotrophs (consumers). Food Chains  A series of steps in which organisms transfer energy by eating and being eaten Food Webs Trophic Levels

Feeding Relationships

Energy flows through an ecosystem in one direction, from the sun or inorganic compounds to autotrophs (producers) and then to various heterotrophs (consumers). Food Chains  A series of steps in which organisms transfer energy by eating and being eaten Food Webs  Link all food chains in an ecosystem together Trophic Levels

Feeding Relationships

Energy flows through an ecosystem in one direction, from the sun or inorganic compounds to autotrophs (producers) and then to various heterotrophs (consumers). Food Chains  A series of steps in which organisms transfer energy by eating and being eaten Food Webs  Link all food chains in an ecosystem together Trophic Levels  Each step in a food chain or food web (1 st, 2 nd, 3 rd, etc.)

Ecological Pyramids A diagram that shows the relative amounts of energy or matter contained within each trophic level in a food chain or food web 3 Kinds:  Energy Pyramid  Biomass Pyramid  Pyramid of Numbers

Ecological Pyramids Energy Pyramids Only about 10% of the energy available within one trophic level is transferred to organisms at the next trophic level Most energy consumed is…  used for life processes and  released as heat

Ecological Pyramids Biomass Pyramid  Total amount of living tissue within a given trophic level  Grams of organic matter per unit area  Potential food available

Ecological Pyramids Pyramid of Numbers  Shows numbers of individual organisms at each trophic level  Not always “pyramid” shape