Biogeochemical Cycles 39 Flashcards
Biogeochemical cycle
These cycles allow us to follow the flow of nutrients through ecosystems.
Living organisms require six elements
C, H, O, N, S, P
Nitrogen Cycle
Nitrogen is found in aa, plants use NO3- and NH4+. N2 from our atmosphere is unavailable.
N2 in our environment comes from?
5-10% from rain. Atmospheric fixation or nitrogen fixation.
Nitrogen fixation is found in
Bacteria and archaea. This requires ATP as well as enzymes.
Soil, root nodules of legumes, and live with organisms.
Gives NH3+ to become NH4+ which is used by plants.
NH4+ is used b aerobic bacteria for energy
Its oxidized into NO2- and NO3-
Denitrification
This denitrification process is done by certain bacteria. They live in anaerobic mud of lakes, bods, estuaries, and on the sea floor.
Bacteria include pseudomonas and bacillus.
Anaerobic conditions.
Decomposers also release xs N
Ammonification
2NH3 + 3O2 -> 2NO2- + 2H+ +2H2O
2 NO2- + O2 -> 2NO3-
Carbon cycle
CO2 balance
CO2 comes from cellular respiration, fossil fuel burning, volcanic eruptions, and bacterial decomposers.
Photosynthesis CO2-> O2.
Atmosphere and Ocean.
Ocean in carbon cycle
Main carbon reservoir. Ocean contains 3/4 of the carbon in the form of HCO3- and CO3- and a small percentage in dead organic matter and phytoplankton.
CO2 blanket
Absorbs heat from the sun. Increases temp of the Earth.
Phosphorus Cycle
P is found in ATP, DNA, RNA, and cell membrane. P is also needed by animals for bones, teeth, and shells. Only solid, sedimentary cycle.
Sedimentary rocks or marine origin is where the largest phosphorous accumulations are. Phosphorus does not enter the atmosphere.
Main points Phosphorus
1) Weathering over time causes rocks to release some phosphorus in the form of PO4—, inputted in soil and water.
2) Plants take up soil with PO4—, which are eaten by animals.
3) In soil, bacteria can allow P to be made available to plants
Eutrophication
Bacteria and algae experience an intense exponential growth which uses up all the available O2. Kills off many species in the marine ecosystem.
H bonding properties
a) Abnormall high boiling point
b) Low vapor pressure
c) High surface tension
d) Solid phase less dense than liquid phase
Water cycle
Occurs between ocean and atmosphere though evaporation and precipitation.
H2O evaporates from oceans, it cools and condenses to form clouds. It rains and becomes groundwater.
G-> L is condensation, exothermic, environment is heated - delta H.
Burning fossil fuels
elevates CO2 levels, increase temperatures can cause sea levels to rise.
Acid Rain
Emissions of SO2 and N oxides react with H2O to produce acidic compounds. Burning of coal is a large cuplrit.
Deforestation
Loss of habitat to millions of species. Removing trees deprives the forest of its canopy. The canopy blocks the sun’s rays during the day and holds heat at night. Temperature swings can occur that will harm animals and plants. Tree help absorbe greenhouse gases.
