AP ENV CHAP 3.4

What are three ways in which your life would be different if there were no special forces of attraction (hydrogen bonds) between water molecules?

1) Without water's high boiling point, the oceans would have evaporated long ago. 2) •It takes a large amount of energy to evaporate water because of the forces of attraction between its molecules. 3)•The forces of attraction between water molecules also allow liquid water to adhere to a solid surface.

three ways in which we directly or indirectly affect the nitrogen cycle?

1)- Nitrates from fertilizer runoff and decomposition=Ammonia in soil = 2) Nitrogen in ocean sediments 3)- Nitrogen oxides from burning fuel and using inorganic fertilizers

The Carbon Cycle

Carbon is the basic building block of the carbohydrates, fats, proteins, DNA, and other organic compounds necessary for life. .

The Nitrogen Cycle: Bacteria in Action

Nitrogen is a crucial component of proteins, many vitamins, and nucleic acids such as DNA The nitrogen cycle consists of several major steps. In nitrogen fixation, specialized bacteria in soil as well as bluegreen algae (cyanobacteria) The bacteria use some of the ammonia they produce as a nutrient and excrete the rest into the soil or water. Some of the ammonia is converted to ammonium ions (NH4 +) that plants can use as a nutrient. . (see p71 nitrogen cycle)

Nutrient cycles connect past, present, and future forms of life.

Some of the carbon atoms in your skin may once have been part of an oak leaf, a dinosaur's skin, or a layer of limestone rock. ( by inhalation)

The Sulfur Cycle

Sulfur circulates through the biosphere Plant roots absorb sulfate ions and incorporate the sulfur as an essential component of many proteins.

biogeochemical cycles or nutrient cycles.

The elements and compounds that make up nutrients move continually through air, water, soil, rock, and living organisms within ecosystems, as well as in the biosphere in cycles. =life-earth-chemical cycles

the hydrologic cycle can be viewed as a cycle of natural renewal of water quality.

We alter the water cycle in three major 1) -we withdraw large quantities of freshwater from streams, 2)- we clear vegetation from land for agriculture,mining, road building, and other activities. This increases runoff, reduces infiltration that would normally recharge groundwater supplies, 3)-we also increase flooding when we drain and fill wetlands for farming and urban development.

Human activities are affecting the phosphorous cycle

an reducing phosphate levels in tropical soils by clearing forests Phosphates in mining waste ( runoff lakes) Phosphates in sewage ( runoff rivers) Phosphates in fertilizer ( runoff rivers) ( see Phosphate cycle p73)

Human activities have affected the sulfur cycle

by releasing large amounts of sulfur dioxide (SO2) into the atmosphere; mining extraction,burning coil, smelting, rifining fossil fuel, consequence = Sulfuric Acid and Sulfate deposited as acid rain

The carbon cycle is based on

carbon dioxide (CO2)gas, which makes up 0.039% of the volume of the earth's atmosphere and is also dissolved in the water cycle) is a key component of the atmosphere's thermostat. (SEE p70 FOR CO2 CYCLE)

The Water Cycle or Hydrologic cycle

collects, purifies, and distributes the earth's fixed supply of water, The water cycle is powered by energy from the sun and involves three major processes—evaporation, precipitation, and transpiration. Transpiration, water evaporate from the surface of plant.

Human activities are degrading the earth's natural capital by..

increasingly altering the rates at which energy flows through these cycles and the rates at which critical chemicals are recycled.

▲Nutrients Cycle within and among Ecosystems

of the three principles of sustainability (see THE biogeochemical cycles or nutrient cycles.

an important component of the earth's natural capital = biogeochemical cycles

solar energy and the earth's gravity, include the hydrologic (water), carbon, nitrogen, phosphorus, and sulfur cycles. and human activities are altering them

The Phosphorus Cycle

which are a combination of phosphorus and oxygen and which serve as an important nutrient. the phosphorus cycle does not include the atmosphere. phosphates are a component of biologically important molecules such as nucleic acids