FLOW of MATTER and ENERGY

EOC Lesson 11: Energy flow through an ecosystem

Where does most of the original energy come from?

Producers Consumers Decomposers

Use absorbed light to make their own food through photosynthesis

An organism that obtains its food by eating other organismsClassified based on their food sourcePrimary and secondary consumers

Gets energy by breaking down the remains of dead organismsReturn chemicals to environment

Plants, green algae, and some bacteria

All animals, many protists, some bacteria

Fungi, many types of bacteria

Trophic levels and food chain• Trophic level = each feeding level• Food chain is used to show the energy flow from one organism to the

next

Food web• Food chain has only 1 path for the flow of energy. Food webs are used

to represent several food chains because there are more than one producer and decomposer.

Herbivores Carnivores Omnivores

Feed on or almost entirely on plants

Feed on or mainly on animals

Eats both plants and animals

Energy Pyramid• Shows the energy loss between the trophic levels in an ecosystem• Only about 10% of the energy is passed from one trophic level to the

next• Rest is “lost” to the environment as heat

Lesson 12: aerobic and anaerobic respiration

Chemical energy• Stored in carbohydrates and other organic compounds• Used for cellular activity• Released through the process of respiration• Mitochondria is the organelle that releases the energy• This energy is stored in a compound = ATP (adenosine triphosphate)

ATP – nucleotide and 2 phosphate groups. Loses a phosphate to release energy and becomes ADP.

Aerobic vs. anaerobic• Aerobic • Requires oxygen• cellular respiration• Produces a lot of energy

• Anaerobic • Does not require oxygen• Fermentation• Produces a little energy

Cellular respiration• Takes place in the mitochondria• C6H12O6 + 6O2 6 CO2 + 6 H20 + energy

Glycolysis Krebs Cycle (if oxygen is present)

Electron transport chain

Splits glucose molecule into pyruvic acidcytoplasmProduces 2 ATPOccurs in both aerobic and anaerobic respiration

Also known as citric acid cycleTakes place in mitochondriaBreaks down pyruvic acid into carbon dioxide and ATP

High energy electrons from Krebs cycle to convert ADP to ATPTakes place in mitochondria

Together produce 36 ATP molecules = total of 38 ATP

Lactic Acid Fermentation Alcoholic FermentationConverts pyruvic acid into lactic acidYogurt and cheeseMuscles during strenuous excerise

Convert pyruvic acid into ethyl alcoholWine, beer, bread

Both processes are anaerobic respiration

Lesson 13: Photosynthesis and Cellular Respiration

Photosynthesis•RAW materials: carbon, hydrogen, oxygen•Use sunlight for energy•Carbon dioxide + water + glucose + oxygen

• Takes place in the chloroplast

Lesson 14: Biogeochemical Cycles

4 systems that make up earth• Land• Air• Water• And organisms

• These processes can be altered by human activities or by natural events

Biogeochemical cycles and Reservoirs• Biogeochemical cycles• Connection between livings things and Earth’s systems• Involve the movements of organic and inorganic chemicals through the

lithosphere, hydrosphere, atmosphere, and biosphere

• Reservoirs• Places where various chemicals are stored and from which they flow and are

recycled• Carbon from rocks, as gas in atmosphere, and dissolved in water in tissues

4 main processes of the water cycleEvaporation Transpiration Condensation Precipitation

Water changing from liquid to a gas

Movement of water from plants into the air from the openings in their leaves

Water vapor turns to liquid

Water that falls back to earth into bodies of water, land to be absorbed or flow off as runoff to resevoirs

Altered water cycle: impact on environment• create dams which displace plants and animals which lived there, they

can no longer reach their breeding grounds• Irrigation• Climate change: increase in global temperatures change the patterns

of precipitation and evaporation

Nitrogen cycle – continuous movement of nitrogen through each of Earth’s systems• 78% of Earth’s atmosphere• Bacteria plays a critical role in the nitrogen cycle. Since most living

things cannot use it directly, bacteria convert the nitrogen gas to ammonia and nitrates which can be used.• Used to make proteins• Overplanting of crops uses up the nitrogen in the soil, clear-cutting of

forest expose soil to erosion carrying away nitrogen-rich soil, artificial fertilizers run off into nearby bodies of water causing an overgrowth of algae (algal blooms) which in turn uses up oxygen and kills off the organisms that lived in this ecosystem

Carbon-oxygen cycle: two cycles that are studied together between atmosphere and living things. • Includes photosynthesis and cellular respiration• Oxygen is used to burn fuel

• death and decomposition of living things forms fossil fuels which store large amounts of carbon

• Effects: combination of forest destruction and burning of fossil fuels increases the amount of carbon in the atmosphere. As a result, there is an increase in temperature all over the planet.