NUTRIENT CYCLES GEOCHEMICAL CYCLES Movement of a particular

NUTRIENT CYCLES

GEOCHEMICAL CYCLES Movement of a particular form of matter through the living and nonliving parts of an ecosystem Earth is a closed system…must continually recycle essential matter (Matter is neither created nor destroyed)

THE CARBON CYCLE n Carbon is especially important to living systems because it is the key ingredient in all living organisms…Proteins, carbohydrates, lipids, nucleic acids

PROCESSES IN THE CARBON CYCLE Photosynthesis n Respiration n Decomposition of plants and animals n Conversion of biochemical compounds n

OTHER PROCESSES IN THE CARBON CYCLE n Combustion n When wood or fossil fuels are burned, CO 2 is released into the atmosphere

OTHER PROCESSES IN THE CARBON CYCLE n Weathering of carbonate rocks Bones/shells fall to the bottom of oceans/lakes & are incorporated into sedimentary rocks n When they decompose, Carbon is released into ocean, atmosphere n

THE NITROGEN CYCLE Why do we need nitrogen? n Nitrogen is necessary for organisms to make amino acids… …which are needed to build proteins!!! n

NITROGEN RESERVOIRS In the atmosphere as elemental nitrogen (N 2) n 78% of the air is N 2 gas n In living organisms as proteins or nucleic acids n In organic materials that compose soil n

PROCESSES IN THE NITROGEN CYCLE n NITROGEN FIXATION: Nitrogen fixing bacteria-found in soil, root nodules of plants n Convert elemental nitrogen into forms that are available for use by plants n They “fix” it for the plants n

PROCESSES IN THE NITROGEN CYCLE n NITROGEN INTAKE: Plants take in nitrogen through root systems in the form of ammonia or nitrate n This is how nitrogen enters the food chain. n

PROCESSES IN THE NITROGEN CYCLE n DECOMPOSITION: When an organism dies or animals produce waste products n Decomposers return nitrogen to the soil n

PROCESSES IN THE NITROGEN CYCLE n DENITRIFICATION: Denitrifying bacteria break down nitrogen compounds in the soil n Release elemental nitrogen into the atmosphere n “De” undo, reverse n

THE WATER CYCLE AKA: THE HYDROLOGIC CYCLE Water is a necessary substance for the life processes of all living organisms

THE WATER CYCLE AKA: THE HYDROLOGIC CYCLE n PRECIPITATION: n. The process in which water (in the form of rain, snow, sleet, or hail) falls from clouds in the sky.

THE WATER CYCLE AKA: THE HYDROLOGIC CYCLE n EVAPORATION: n n Water changing from a liquid to a gas TRANSPIRATION: n Evaporation of water from a plant’s leaves

THE WATER CYCLE AKA: THE HYDROLOGIC CYCLE n CONDENSATION: Water vapor (a gas) in the air turns into liquid water. (Condensing water forms clouds in the sky. ) n As water vapor condenses— impurities (such as dust) are removed from the atmosphere and fall to Earth with precipitation n

THE WATER CYCLE AKA: THE HYDROLOGIC CYCLE n ACCUMULUATION: n n Water pools in large bodies (oceans, seas and lakes). SEEPAGE: n Water entering the ground

THE WATER CYCLE AKA: THE HYDROLOGIC CYCLE n RUN-OFF: As water travels through soil and rock, it is physically filtered of impurities (filtration) n Water flow slows—heavier particles settle out and purified water continues toward oceans n

THE WATER CYCLE AKA: THE HYDROLOGIC CYCLE n Also remember… Water is also returned to the environment during cellular respiration! C 6 H 1206 + O 2 CO 2 + ATP + H 2 O n

O 2 -CO 2 balance…plants need to produce enough O 2 n Oxygen produced by plants is also responsible for the ozone layer n n Prevents much of the Sun’s UV radiation from reaching Earth’s surface

The story of my fish tank…

AMMONIA (NH 3) is released through respiration & excretion Ammonia is very deadly in high concentrations—so enough fish producing ammonia in a small space (like an aquarium)…will kill the fish.

n Well, this doesn’t have to happen… Bacteria present in an aquarium will feed on ammonia producing nitrites…another bacteria will feed on nitrites producing nitrates… n Nitrates are not nearly as harmful, and much, much easier to control. You would need OBSCENE amounts for it to do any real damage. n