ENERGY FLOW THROUGH THE ENVIRONMENT

Energy must constantly be added to the biosphere as it is constantly lost from living

organisms mainly in the form of heat.

Energy is added

Energy is lost

Energy is lost

GEOCHEMICAL or NUTRIENT CYCLES

• Unlike energy, matter is not added to or lost from the environment.

• Recall: – The law of conservation of matter

states that “matter is not creatednor destroyed in any chemical or physical change”

• All the atoms & molecules on earthare constantly recycled.

WATER CYCLE http://www.youtube.com/watch?v=UDyPkjQxkas&feature=related The Water Cycle Cartoon

Sun heats Earth Water evaporates rises

cools condenses forms clouds.Water droplets size fall (precipitation).Water returns to oceans,

• run off(over land erodes rocks etc)• percolation(to ground water)

Water enters biosphere via plants & animals.

Transpiration(plants)/Perspiration & Excretions(animals)

Evaporation (lithosphere, hydrosphere). Cycle begins again http://wn.com/water_cycle_magic_school_bus_full_episode (MSB 25 min)

WATER CYCLE

CARBON CYCLE https://www.youtube.com/watch?v=dDBU0lg-HYE (5.5 min)

The Carbon CycleGlucose(Sugar)

Photosynthesis Respiration

Carbon Dioxide

•Photosynthesis uses carbon dioxide to store energy in glucose.

•Respiration uses glucose release energy & carbon dioxide.

CARBON CYCLE http://www.youtube.com/watch?

v=vfMgeBfTug4&feature=related (3 parts about 7.5min)

http://www.youtube.com/watch?v=DP24BceOwt8(2 min)

Nitrogen: •About 70% of atmosphere is inorganic N2. •Needed for protein & nucleic acid (NO3 - nitrate)

NITROGEN CYCLE

• The triple bond of N2 is VERY hard to break.

• Only bacteria(land) & cyanobacteria(water) can break the bond converting (N2) into ammonium & nitrates that plants can use.

• Without bacteria there would be no protein!

• Bacteria are also needed to convert NO3 back to N2

NITROGEN CYCLE http://www.youtube.com/watch?v=IaGNSmQQmBc&feature=related (15 min)

PHOSPHORUS CYCLE• Phosphorus (P) is a key element in:

– cell membranes, – ATP (cellular energy), – DNA & other nucleic acids, – calcium phosphate of bones.

• The phosphorus cycle is different from other cycles as there is no phosphorus gas in the atmosphere. 

• Phosphorus cycles in two ways: – a long-term cycle involving the rocks of the Earth's

crust. – a short-term cycle involving living organisms

(phosphate).

PHOSPHORUS CYCLE

Phophorus Cyclehttp://www.youtube.com/watch?v=sMJRuHk9JkA (2min)

Nitrogen & Phophorus Cyclehttps://www.youtube.com/watch?v=leHy-Y_8nRs (9.5min)

PHOPHORUS CYCLE

Human Interference in Nutrient Cycles• Phosphates: - in some detergents & fertilizers.• Nitrates: in fertilizers. • Over use of these nutrients overgrowth of algae & bacteria in rivers and lakes

•This causes “Eutrophication”• Sun is blocked light for other plants oxygen. • Biomass decay oxygen other organisms.

• The burning of fossil fuels CO2 contributes to climate change.• Climate change affects the water cycle & the water cycle affects everything else (erosion etc).