Energy Flow

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Energy Flow

• All organisms use energy
• 1 job each day for life is GET ENERGY
• Food energy
• Some can use non-food energy sources
• Others need to get energy from other organisms

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• Organisms that can make their own food from
  energy and inorganic materials are known as
  producers or autotrophs
• they produce organic molecules (carbohydrates,
  proteins, etc.) from inorganic molecules

Chemosynthetic bacteria
Corn plants
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Those producers that use the sun as their
energy source are known as photoautotrophs which
include plants, algae, some bacteria and many
single-celled organisms
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Photosynthesis

• Photoautotrophs use a process called
  photosynthesis to create organic molecules (food)
  in which the sun is the energy source

Inorganic chemicals sunlight organic chemicals
Simple version
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• Some deep-water bacteria, for example, are
  producers without using sunlight
• They produce organic molecules using inorganic
  molecules and without sunlight
• This is a process known as chemosynthesis
• this isnt a very common process most producers
  use sunlight

Bacteria happily live here at 400 deg F and
pressures that would crush a submarine
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Consumers

• Organisms that cannot make their own organic
  molecules must eat other organisms and use theirs
• Since they consume other creatures they are
  known as consumers
• some consumers eat dead organic matter they are
  still considered consumers because they are
  consuming already existing organic matter

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Types of Consumers

• Herbivores feed exclusively on plant matter
• Ex. cardinals, bees, fruit bats, cows, certain
  fish
• Carnivores feed exclusively on animal tissue
• wolves, eagles, frogs, rattlesnakes, sharks,
  spiders
• Omnivores feed on both plant and animal matter
• Bears, humans, chimps, chickadees, crayfish
• Detritivores eat dead plant / animal matter
• Earthworms, crabs, some beetles, many insect
  larvae
• Decomposers same as above but digest food
  outside
• body and absorb
  nutrients
• MANY types of bacteria, any fungus

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Energy Transfer

• Feeding is about 2 things
• Obtaining energy (1 reason)
• Obtaining organic molecules (amino acids,
  nucleotides, etc)
• Communities are structured mostly based on these
  relationships
• numbers of prey determine of predators
  (different s depending on size of each)
• Producers (their size and availability) are most
  important

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• Example wheat plant and 3 herbivores

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Food Chains Webs

• A food chain is a particular pathway of energy
  transfer in a community
• Almost always begins with a producer
• May involve a series of consumers
• Each step in a food chain is called a trophic
  level and energy is passed from one trophic level
  to the next as organisms feed on those before
  them in the chain

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• The first consumer in a food chain is known as a
  primary consumer (primary 1st)
• This organism is usually an herbivore (may be an
  omnivore)
• The second is known as a secondary consumer and
  may be either a (carnivore or omnivore)
• Third consumer and beyond follow the same pattern
  as the second

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Food chains are limited in length. Why?

• Energy taken in by organisms at each trophic
  level is used up
• Used energy goes toward maintenance,
  reproduction, growth, or is lost in wastes
• On average, only about 10 of energy from each
  trophic level gets passed on when an organism is
  eaten

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• Food chains only show 1 possible path of energy
  flow
• Food webs show many possibilities
• Shows better the true interrelationships within
  the community -- everybody is connected

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Ecological Pyramids

• Diagrams that show the numbers, biomass or energy
  present at each trophic level in an ecosystem

Energy pyramid
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Biomass Pyramid
Numbers Pyramid