Biogeochemical Cycles 39

Question 1

Biogeochemical cycle

Answer 1

These cycles allow us to follow the flow of nutrients through ecosystems.

Question 2

Living organisms require six elements

Answer 2

C, H, O, N, S, P

Question 3

Nitrogen Cycle

Answer 3

Nitrogen is found in aa, plants use NO3- and NH4+. N2 from our atmosphere is unavailable.

Question 4

N2 in our environment comes from?

Answer 4

5-10% from rain. Atmospheric fixation or nitrogen fixation.

Question 5

Nitrogen fixation is found in

Answer 5

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.

Question 6

NH4+ is used b aerobic bacteria for energy

Answer 6

Its oxidized into NO2- and NO3-

Question 7

Denitrification

Answer 7

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.

Question 8

Decomposers also release xs N

Answer 8

Ammonification
2NH3 + 3O2 -> 2NO2- + 2H+ +2H2O
2 NO2- + O2 -> 2NO3-

Question 9

Carbon cycle

Answer 9

CO2 balance
CO2 comes from cellular respiration, fossil fuel burning, volcanic eruptions, and bacterial decomposers.
Photosynthesis CO2-> O2.
Atmosphere and Ocean.

Question 10

Ocean in carbon cycle

Answer 10

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.

Question 11

CO2 blanket

Answer 11

Absorbs heat from the sun. Increases temp of the Earth.

Question 12

Phosphorus Cycle

Answer 12

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.

Question 13

Main points Phosphorus

Answer 13

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

Question 14

Eutrophication

Answer 14

Bacteria and algae experience an intense exponential growth which uses up all the available O2. Kills off many species in the marine ecosystem.

Question 15

H bonding properties

Answer 15

a) Abnormall high boiling point
b) Low vapor pressure
c) High surface tension
d) Solid phase less dense than liquid phase

Question 16

Water cycle

Answer 16

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.

Question 17

Burning fossil fuels

Answer 17

elevates CO2 levels, increase temperatures can cause sea levels to rise.

Question 18

Acid Rain

Answer 18

Emissions of SO2 and N oxides react with H2O to produce acidic compounds. Burning of coal is a large cuplrit.

Question 19

Deforestation

Answer 19

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.