Nutrition and Energy Flow

Energy Energy is the ability to cause change. It is necessary to carry out the function of life. The ultimate source for energy in our solar system is our Sun In order to use any energy it must be converted into a usable form. Ex: thermal energy

In the living world the energy still comes from the sun Autotroph (producers) are the first step in the conversion chain after the sun. Perform photosynthesis. Typically green in color. Auto= self Troph= food

Heterotrophs (consumers) are the second level of conversion. 4 types of heterotrophs Herbivore Carnivore Omnivore Decomposer

Herbivore Plant eaters Herba=grass Vorare= to devour (consume) Typically first order heterotrophs Ex: Rabbits, grasshoppers, beavers, squirrels, bees, elephants, fruit-eating bats, and some humans

Carnivore Meat eaters Caro=flesh Vorare= to devour Typically second order heterotrophs Ex: Lions, tigers, hawks, owls, dogs, etc.

Omnivore Eats both plants and animals Ominus=all Vorare=to devour Typically third order heterotrophs. Ex: Bears, mice, raccoons, most humans, etc.

Decomposers Break down complex compounds into simpler molecules. This include releasing things like carbon stuck in a dead body back into the environment so it can make a new body for some other organism. They play a key part in most of the nutrient cycles in biology Ex: Bacteria, fungi, protozoans, etc

Content Check What is an autotroph? What is a carnivore? What is the difference between a first level heterotroph and a third level heterotroph? A fungus is an example of what?

Content Check Answers What is an autotroph? What is a carnivore? A producer that creates its own food What is a carnivore? A meat eater (only eats meat) What is the difference between a first level heterotroph and a third level heterotroph? 1st level eats producers, 3d level eats animals that ate the 1st level A fungus is an example of what? Decomposer

Energy and Matter Flow In order to trace the flow of energy and matter in a an ecosystem we use food chains and webs. Each level in a food chain or web is called a trophic level.

Food Chains and Webs

Ecological Pyramids Another way to analyze the flow of nutrients and energy is to use ecological pyramids. There are three main pyramids we will go over Energy Numbers Biomass

Pyramid of Energy Describes the amount of energy at each trophic level Each level only has 10% of the previous level. The other 90% is lost as heat. Parasites, scavengers, and decomposers feed at all levels

Pyramid of Numbers Describes the number of organisms available at each level.

Pyramid of Biomass Describes how much each level above needs to consume to meet its need.

Content Check Compare food chains and webs. Each link in a food chain or web represents what? Explain the interactions among organisms in the three different pyramids. How much energy is lost to heat at each level? What does the law of conservation of mass and energy mean?

Content Check Compare food chains and webs. Food chains imply that the removal of a link stops the flow of energy. Food webs show a more accurate representation of what is happening. Both show how energy flows through the system. Each link in a food chain or web represents what? A trophic level Explain the interactions among organisms in the three different pyramids. Pyramid of energy= shows how energy transfers though the system Pyramid of numbers= shows how numbers between levels differ Pyramid of biomass= shows how much material is needed to make the amount at the next level How much energy is lost to heat at each level? 90% What does the law of conservation of mass and energy mean? We have a set amount of both and can neither gain nor loose it, just change its appearance and availability.

Biogeochemical Cycles Matter is not used up, it is transformed. (the same molecules are passed around the system) This is an example of conservation of mass. We will look at 4 types of cycles for this class Water Carbon Nitrogen Phosphorus.

Water Cycle Evaporation Precipitation Condensation Transpiration Runoff Ground water

Carbon Cycle Photosynthesis Respiration Combustion Fossil fuels

Nitrogen Cycle

Phosphorus cycle