Irma Mustika sari
Samsinar
Mega Kusuma Putri
Rosita
Zakaria
BIOGEOCHEMICAL
CYCLES

BIOGEOCHEMICAL CYCLES
• It is a well known fact that there is only a limited
amount of essential elements that are present on earth.
Most people would think, because of that fact, we
should have run out of these essential elements ages
ago. This would be true if it wasn’t for
the biogeochemical cycles. This “recycles” essential
chemical elements within the earth’s atmosphere. It is
able to do this by sending these elements through
biotic or abiotic (living and non-living) pathways.

The Carbon Cycle

• Carbon is a major part of the framework for the
original molecules essential to all organisms.
Carbon is released into the atmosphere by two
main processes; these can be recognized as the
burning of fuel as well a cellular transpiration by
producers and consumers. What removes vast
amounts of CO2 from the atmosphere is a process
known as photosynthesis by plants, algae, and
cyanobacteria. What has been adding even more
substantial CO2 into the atmosphere is the burning
of fossil fuels which has been connected to global
warming.

Carbon-Oxygen Cycle

Phosporous Cycles

• Phosphorus is a major element within energy storing
molecules (for ATP, Phospholipids, and Nucleic
acids). Phosphate is added gradually added to the soil
by the weathering of rocks. Some finds its way into
the bodies of water while others are eventually eaten
by consumers and travels within the food chain.
Decomposition returns Phosphate into the soil. Only
relatively small amounts of phosphate are present
within the atmosphere because there are no
significant phosphorous containing gases; it usually
travels as dust or spray.

Sulphur Cycles

• Compared to CO2 and N2 naturally occuring sulfur is "already
fixed". Sulfur occurs in nature as sulfate, e.g. gypsum (CaSO4),
(FeS2) and elemental sulfur. The sulfate concentration in the ocean
is 2.4 g/L. In anearobic waters, sedimentary organisms generate
hydrogen sulfide. The atmospher contains SO2 gas (released by
volcanic activity). Sulfate is reduced to organic sulfur compounds
(R-SH) by plants, fungi and bacteria. Sulfate reducing bacteria
generate hydrogen sulfide (H2S) from sulfate and photosynthetic
green and purple sulfur bacteria as well as some chemolithotrophs
oxidize hydrogen sulfide to elemental sulfur. Organic sulfur
compounds such a dimethyl sulfide are released into the ocean by
algae.