Nutrient CyclesNutrient CyclesNutrient Cycling

Carbon CycleGlobal WarmingNitrogen Cycle

Nutrient CyclesNutrient Cycles

95% of an organism is made up of only six elements:

Carbon – from CO2 to all organic molecules

Oxygen – from CO2 to all organic molecules

Hydrogen – from H2O to all organic molecules

Nitrogen – from nitrates to all proteins

Phosphorous – phosphates to proteins

Sulphur – sulphates to proteins

Nutrient CyclesNutrient Cycles

95% of an organism is made up of only six elements:

Carbon – from CO2 to all organic molecules

Oxygen – from CO2 to all organic molecules

Hydrogen – from H2O to all organic molecules

Nitrogen – from nitrates to all proteins

Phosphorous – phosphates to proteins

Sulphur – sulphates to proteins(Photosynthesis)

Nutrient CyclesNutrient Cycles

95% of a living organism is made up of only six elements:

Carbon – from CO2 to all organic molecules

Oxygen – from CO2 to all organic molecules

Hydrogen – from H2O to all organic molecules

Nitrogen – from nitrates to all proteins

Phosphorous – phosphates to proteins

Sulphur – sulphates to proteins

(absorbed from soil by roots of plants)

Nutrients in air soil and water

Producers

consumers

decomposers

photosynthesis

feeding

decay

respiration and excretion

feeding

Unavailable organic nutrients coal, oil, peat

Unavailable inorganic nutrients, mineral in rocks

fossilisation

burning erosion

The Carbon CycleThe Carbon Cycle

What is a carbon sink?

The Carbon CycleThe Carbon Cycle

burning

respiration

photosynthesis

Global Warming and the Greenhouse EffectGlobal Warming and the Greenhouse Effect

The Greenhouse EffectThe Greenhouse Effect

G.H. gases don’t absorb visible wavelengths of light

What would reflect solar radiation?

What form does the energy become when absorbed by the Earth?

G.H. gases can absorb and re-emit infra red radiation

Global DimmingGlobal Dimming

The Effects of Global WarmingThe Effects of Global Warming

Is the conclusion that the Earth’s global temperature is increasing valid?

Can you criticise the conclusion?

Is this evidence that humans are the cause?

The Effects of Global WarmingThe Effects of Global Warming

Is this evidence that humans cause global warming?

Any criticisms?

Global Warming and Crop YieldsGlobal Warming and Crop Yields

Why are food prices predicted to increase due to global warming?

How will increased CO2 effect crop yields?How will increased temperature effect crop yields?So what’s the problem….?

Global Warming and Crop Yields: RiceGlobal Warming and Crop Yields: Rice

Maximum

temperature

Minimum temperature

Light Intensity

How Science Works:1.Which variable would you control?2.Can you explain why you need to control each variable?3.What would you do if you couldn’t control a particular variable?

Global Warming and Crop Yields: RiceGlobal Warming and Crop Yields: Rice

Is there a correlation?

What is the relationship

between yield and minimum

temperature?

What is the relationship

between yield and light

intensity?

Global Warming and Crop Yields: RiceGlobal Warming and Crop Yields: Rice

What has the biggest effect on yield?Which factors will change due to global warming?How can we explain this effect?

Global Warming and MigrationGlobal Warming and MigrationWhat will happen to these biomes as the global temperature increases?

How will organisms respond?

Describe this in terms of niches.

Global Warming and MigrationGlobal Warming and Migration

Global Warming and Crop PestsGlobal Warming and Crop Pests

How will global warming effect insect pests?

Why will new pests be able to survive in the UK?

Crop yields will decrease unless…

How will global warming change our farming practices?

Its all about the bacteria!

Its all about the bacteria!

Nutrients in air soil and water

Producers

consumers

decomposers

photosynthesis

feeding

decay

respiration and excretion

feeding

Unavailable organic nutrients coal, oil, peat

Unavailable inorganic nutrients, mineral in rocks

fossilisation

burning erosion

The Nitrogen CycleThe Nitrogen Cycle

Why do living organisms need nitrogen?

What is the largest nitrogen sink on the planet?

What is the problem with N2 gas as a source of nitrogen?

The Nitrogen CycleThe Nitrogen Cycle

Nitrogen-fixing bacteria in root nodules.

Nitrogen-fixing bacteria

The Nitrogen CycleThe Nitrogen Cycle

Nitrogen Fixing Bacteria

“Free living” in soil: Azobacter, Clostridium

Mutualism in plants: Rhizobium

In aquatic systems: Cyanobacteria

Lightning

Provides energy needed to break N2 bonds

Produces Nitric Acid

Dissolves in rain, adding nitrate ions to soil

Nitrogen CycleNitrogen Cycle

Rhizobium and Leguminous Plants:

Invade plant through root hairs

Live in specialised root nodules

Nitrogen CycleNitrogen Cycle

1) Plant releases chemicals2) Bacteria attracted to root3) Bacteria trigger cell division

4) Infection5) Nodule formation8) Nodule has vascular tissue

Nitrogen CycleNitrogen Cycle

All nitrogen fixing is carried out by Nitrogenase

16ATP 16 ADP

+ 16Pi

8 NADH+H+

NAD+

N2 2NH3 + H2

Where does all the energy come from?

What industrial process achieves this reaction?

Nitrogen CycleNitrogen Cycle

All nitrogen fixing is carried out by Nitrogenase

16ATP 16 ADP

+ 16Pi

8 NADH+H+

NAD+

N2 2NH3 + H2

NH3 is toxic, bacteria and plant quickly convert it to glutamine.

What is glutamine?

Why is this a mutualistic relationship?

glutamine

The Nitrogen CycleThe Nitrogen Cycle

Nitrogen-fixing bacteria in root nodules.

Nitrogen-fixing bacteria Nitrite bacteria

Nitrate bacteria

Nitrogen CycleNitrogen Cycle

Nitrifying Bacteria

NH3 dissolves readily in soil water

NH3 + H+ NH4+

Nitrite bacteria: Nitrosomonas

2NH4 + 3O2 2NO2- + 2H2O + 4H+

Nitrate bacteria: Nitrobacter

2NO2- + O2 2NO3

-

Nitrate ions diffuse freely in soil water and are more readily absorbed by plants.

What type of reaction do these bacteria carry out?

Nitrogen CycleNitrogen Cycle

Nitrifying Bacteria

NH3 dissolves readily in soil water

NH3 + H+ NH4+

Nitrite bacteria: Nitrosomonas

2NH4 + 3O2 2NO2- + 2H2O + 4H+

Nitrate bacteria: Nitrobacter

2NO2- + O2 2NO3

-

Nitrate ions diffuse freely in soil water and are more readily absorbed by plants.

What is the link with eutrophication in lakes and rivers?

The Nitrogen CycleThe Nitrogen Cycle

Nitrogen-fixing bacteria in root nodules.

Nitrogen-fixing bacteria Nitrite bacteria

Nitrate bacteria

Denitrifying bacteria

Nitrogen CycleNitrogen Cycle

Denitrifying Bacteria

Nitrate ions are washed into water table, rivers, lakes and sea.

Water logged soil and mud is anaerobic

Denitrifying bacteria use NO3- as final electron

acceptor in electron transport chain.

NO3- is broken down in N2 gas, released into

atmosphere.

The Nitrogen CycleThe Nitrogen Cycle

Nitrogen-fixing bacteria in root nodules.

Nitrogen-fixing bacteria Nitrite bacteria

Nitrate bacteria

Denitrifying bacteria

Nitrogen CycleNitrogen Cycle

Ammonification

Ammonia released back into the soil by:

Decomposition of protein (decay) by fungi and bacteria

Excretion from animals

Assimilation

Nitrogen in protein passed along food chain

The Nitrogen CycleThe Nitrogen Cycle

Nitrogen-fixing bacteria in root nodules.

Nitrogen-fixing bacteria Nitrite bacteria

Nitrate bacteria

Denitrifying bacteria

Haber process: fertilisers

Lightning

The Nitrogen CycleThe Nitrogen Cycle

1. What is the relevance of nitrogen fixation in crop rotation?

2. Why is good soil drainage important for gardens and arable land?

3. How can high crop yields be explained in water logged paddy fields?

Fertilisers, Farm Waste and Water Fertilisers, Farm Waste and Water PollutionPollution

1) Why do farmers add fertiliser to their fields?

2) What are the advantages and disadvantages of organic and inorganic fertiliser?

One post per idea. Use your real names! Chemical or Organic?http://www.wallwisher.com/wall/kegschgbiology13A

One post per idea. Use your real names! Chemical or Organic?http://www.wallwisher.com/wall/kegschgbiology13b

EutrophicationEutrophication

“is the natural enrichment of water bodies with nutrients over time” (succession)

Accelerated eutrophication is caused by man.

EutrophicationEutrophication

EutrophicationEutrophication

Fertiliser is leached from fields by rain

Water is rapidly enriched with nutrients

Is inorganic or organic fertiliser worse?

EutrophicationEutrophication

Sewage and farm waste be decomposed by bacteria as well as add nutrients to water.

Eutrophication: Data InterpretationEutrophication: Data InterpretationWhat does this chart suggest about eutrophication in the esturies of the USA?What is the percentage of esturaies with high percentage eutrophication?

Which indicator suggests there is a lot of eutrophication in the USA?What does the Dissolved Oxygen indicator suggest?

Are these conlusions valid?

The East Coast has less eutrophication

Are these conlusions valid?

Eutrophication is caused by an increase in human population

Are these conlusions valid?

Eutrophication is increased by warmer temperatures.

Are these conlusions valid?

Eutrophication is caused by farming.

Eutrophication: The Limiting Factor?Eutrophication: The Limiting Factor?

Eutrophication: the limiting factor?Eutrophication: the limiting factor?