What organism is important in cycling of nutrients? Agenda for Monday Jan 11th Quiz Finish cycles webqwest Cycles Notes NEW SEATS

What is the difference between biomagnification and bioaccumulation? Agenda for Tuesday Jan 12th Cycles notes Photosynthesis graph

Cycles in Earth Law of Conservation of Mass Biogeochemical cycles – exchange of matter through biosphere Reservoirs/sinks – places where matter & nutrients stored Why is it important that nutrients cycle?

Water Cycle Water never leaves the Earth. It is constantly being cycled through the atmosphere, ocean, and land. This process, known as the water cycle, is driven by energy from the sun.

Water Cycle Evaporation – liquid water becomes a gas Transpiration – evaporating off plants Condensation – water changing from gas to liquid

3. Precipitation – water falling to Earth from atmosphere 4. Run-off – water running over the land collect in the oceans, lakes or rivers 5. Infiltration – water seeping into the ground Ground Water- stored in underground caverns and porous rock Provides water for the soil, streams, rivers, and oceans

Human impacts on water cycle Removing forests and vegetation increases runoff and erosion, reduces transpiration and lowers water tables Agriculture Damming rivers increases evaporation and infiltration Emitting pollutants = acid precipitation Most threatening : overdrawing groundwater for drinking, irrigation, and industrial use 9 9

Carbon and Oxygen Cycles The movement of carbon from the environment into living things and back again Carbon is essential because it is part of our molecules and all living things

Where is the carbon? Stored in oceans, plants, air Fossil fuels Many animals pull carbon from water to use in shells, etc. Oceans contain earth’s largest store of carbon Fossil fuels Oil, coal, natural gas Respiration and life processes Methane – cows

Ways carbon moves Photosynthesis – moves from environment to living things Respiration- moves from living things back to the environment Decomposition- moving from dead organisms back to the environment Combustion- Burning fossil fuels releases carbon back into the atmosphere

Photosynthesis Light energy is converted into chemical energy Make sugars 6 CO2 + 6 H2O C6H1206 + 6 O2 Carbon dioxide + water + energy glucose + oxygen LIGHT

Photosynthesis occurs in Chloroplast

Two Phases of Reactions Phase 1: Light-Dependent Reactions Produce ENERGY Phase 2: Light-Independent Reactions Energy is converted and stored in organic molecules Carbon dioxide and energy make Glucose

Uses of Sugars What are the sugars created in photosynthesis used for? Energy Stored energy and instant energy Building blocks for parts in the cell Glucose molecules form polysaccharides Cellulose – structure for cell – structures for plants

Write the equation for photosynthesis. Agenda for Wednesday Jan 13th Photosynthesis graph Photosynthesis demo Respiration

Overview of Respiration C6H1206 + 6O2 6CO2 + 6H2O + ENERGY Organisms use stored energy in glucose 36 ATP per molecule of glucose is made 3 Parts: Glycolysis, Krebs Cycle, and Electron transport Glycolysis is anaerobic – does not require oxygen Aerobic – requires oxygen Electron transport & Krebs cycle

Mitochondria

Anaerobic Respiration No oxygen present: ATP can continue to be created through glycolysis Only 2 ATP produced Glycolysis stops when all NAD+ is used Fermentation – produces a small amount of ATP

Carbon is released into the atmosphere in several ways Respiration by plants and animals. Decay of animal and plant matter. Combustion of organic material The ocean releases CO2 into the atmosphere. Volcanic eruptions and metamorphism

Carbon in the Atmosphere Greenhouse effect Trapping of heat by molecules (water, CO2) Excessive carbon in the atmosphere raises temp.

Human Impact Fossil fuels Deforestation and Habitat Destruction Releases stores of carbon Burning anything releases more carbon into atmosphere Deforestation and Habitat Destruction Fewer plants mean less CO2 removed from atmosphere

Humans affect the carbon cycle Today’s atmospheric carbon dioxide reservoir is the largest in the past 800,000 years It is the driving force behind climate change

Human-Produced Greenhouse Gas Levels

Photo from IPCC

Effects of Climate Change

Sea Level Rise Melting of Expansion of heated (warm) sea water Greenland Ice Sheet Antarctic Ice Sheet Glaciers and ice caps Expansion of heated (warm) sea water Slide compliments of Rei Ueyama 2 – 4 C warming by ~2100  0.18 - 0.59 meter rise in sea level IPCC (2007) 30

Other Effects Ecosystem change Flooding of coastal communities Loss of species Flooding of coastal communities Spread of diseases Increase of extreme weather events

Nitrogen Cycle Nitrogen is used by plants and animals Proteins, nucleic acids Nitrogen is found in atmosphere and is unusable Converted to a useable form through nitrogen fixation Special organisms/bacteria that convert legumes Lightning Animals get nitrogen from eating plants Returned to soil when animals urinates/dies Denitrification – nitrogen is converted back to gas

Humans affect the nitrogen cycle Haber-Bosch process = production of fertilizers by combining nitrogen and hydrogen to synthesize ammonia animal waste Excess Nitrogen can cause Eutrophication causes aquatic life to die due to low levels of oxygen High levels of ammonia is toxic to animals

Decreasing Nitrogen Pollution Scientists, farmers and policymakers are encouraged to Decrease fertilizer use While safeguarding agriculture Using new farming methods Planting cover crops Maintaining wetlands

Humans affect Cycles shifting carbon from fossil fuel reservoirs into the atmosphere shifting nitrogen from the atmosphere to the planet’s surface depleting groundwater supplies