Chapter 5 - Natural Biogeochemical Cycles

Nitrogen

________- Found in many organic molecules, including the amino acids that make up proteins and nucleic acids that make up DNA.

Carbon

________ dissolved in seawater is used for phytoplankton and kelp for photosynthesis.

Phosphorus

________- Found in the bone and in the molecule ATP.

Sulfur

________- Found in 2 amino acids that are important for giving proteins their shape.

Limestone

________ and carbon trapped in fossil fuels and coal.

Forests

________ store 90 % of the planet's aboveground carbon and 75 % of soil carbon.

Assimilation

________- Plants absorb ammonia, ammonium ions, and nitrate ions through their roots.

Nitrification

________- Ammonia is converted into nitrate and nitrite.

Ammonia

________ has tripled since the industrial revolution.

Denitrification

________- Anaerobic bacteria convert ammonia into nitrites, nitrogen gas, and nitrous oxide.

portion of atmospheric carbon

A(n) ________ is removed through photosynthesis in which carbon gets incorporated into plant structures and compounds.

water cycle

The ________ is in a state of dynamic equilibrium by which the rate of evaporation equals the amount of precipitation.

air quality

It decreases ________.

main source of sulfur

The ________ in the oceans is through dissolved sulfate.

Sulfur

________ in the lithosphere is mobilized by slow weathering of rock material.

Nitrogen Fixation

__________________ - Atmospheric nitrogen is converted into ammonia or nitrate ions which are biologically usable forms of nitrogen.

Water

_______ - Helps to dissolve minerals, makes them accessible to the body, regulates body temperature, and carries nutrients and oxygen to cells throughout the body.