BiologyChapter 2, Section 3

Cycling of Matter

Main idea-Essential nutrients are cycled through biochemical processes.

Essential Questions How do nutrients move through biotic and abiotic parts of an ecosystem? Why are nutrients important to living organisms? What are the biogeochemical cycles of nutrients and how are they alike?

I. Cycles in the BiosphereA. Energy is ___________________________ into usable forms to support the functions of an

ecosystem.1. The cycling of nutrients in the ___________________________ involves both matter

in living organisms and physical processes found in the environment such as ___________________________.

2. A nutrient is a chemical ___________________________ that an organism must obtain from its ___________________________ to sustain life and to undergo life processes.

i. Nutrients include water, carbon, nitrogen and phosphorous3. The biogeochemical cycle is the ___________________________ of matter through

the biosphere.B. The Water Cycle

1. Approximately 90 percent of water ___________________________ evaporates from oceans, lakes, and rivers; 10 percent evaporates from the surface of plants through a ___________________________ called transpiration.

i. Freshwater ___________________________ only about 3 percent of all water on Earth.

ii. About 69 percent of all ___________________________ is found in ice caps and glaciers.

C. The Carbon and Oxygen Cycle1. Carbon and ___________________________

often make up molecules essential for ___________________________.

2. Carbon and oxygen recycle relatively ___________________________ through living organisms.

3. Long-term Cyclei. Organic matter

___________________________ to peat, coal, oil, or gas deposits (carbon)

ii. Calcium carbonate (carbon and oxygen)

4. Short-term Cyclei. Burning ___________________________

fuels (carbon)D. The Nitrogen Cycle

1. The ___________________________ and conversion of nitrogen into a form that is useable by plants is called nitrogen ___________________________.

2. Nitrogen enters the food web when ___________________________ absorb nitrogen compounds from soil.

3. ___________________________ get nitrogen by eating plants or animals that contain nitrogen.

4. Nitrogen is ___________________________ to the soil in several ways:i. Animals urinate.

ii. Organisms die.iii. Organisms ___________________________

ammonia into nitrogen compounds.iv. Denitrification

E. The Phosphorous Cycle1. Short-term Cycle

i. Phosphorus is cycled from the soil to ___________________________ and then

from the producers to ___________________________.2. Long-term Cycle

i. Weathering or ___________________________ of rocks that contain phosphorus slowly adds ___________________________ to the cycle.