Week 11 nutrient cycles

Nutrient Cycles Nutrient Cycling Carbon Cycle Global Warming Nitrogen Cycle

Nutrient Cycles 95% of an organism is made up of only six elements: Carbon – from CO 2 to all organic molecules Oxygen – from CO 2 to all organic molecules Hydrogen – from H 2 O to all organic molecules Nitrogen – from nitrates to all proteins Phosphorous – phosphates to proteins Sulphur – sulphates to proteins

Nutrient Cycles 95% of an organism is made up of only six elements: Carbon – from CO 2 to all organic molecules Oxygen – from CO 2 to all organic molecules Hydrogen – from H 2 O to all organic molecules Nitrogen – from nitrates to all proteins Phosphorous – phosphates to proteins Sulphur – sulphates to proteins (Photosynthesis)

Nutrient Cycles 95% of a living organism is made up of only six elements: Carbon – from CO 2 to all organic molecules Oxygen – from CO 2 to all organic molecules Hydrogen – from H 2 O 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 Cycle What is a carbon sink?

The Carbon Cycle burning respiration photosynthesis

Global Warming and the Greenhouse Effect

The 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

The 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 Warming Is this evidence that humans cause global warming? Any criticisms?

Global Warming and Crop Yields Why are food prices predicted to increase due to global warming? How will increased CO 2 effect crop yields? How will increased temperature effect crop yields? So what’s the problem….?

Global Warming and Crop Yields: Rice Maximum temperature Minimum temperature Light Intensity How Science Works: Which variable would you control? Can you explain why you need to control each variable? What would you do if you couldn’t control a particular variable?

Global 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: 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 Migration What will happen to these biomes as the global temperature increases? How will organisms respond? Describe this in terms of niches.

Global 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?

The Nitrogen Cycle Why do living organisms need nitrogen? What is the largest nitrogen sink on the planet? What is the problem with N 2 gas as a source of nitrogen?

The Nitrogen Cycle Nitrogen-fixing bacteria Nitrogen-fixing bacteria in root nodules.

The 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 N 2 bonds Produces Nitric Acid Dissolves in rain, adding nitrate ions to soil

Nitrogen Cycle Rhizobium and Leguminous Plants: Invade plant through root hairs Live in specialised root nodules

Nitrogen Cycle Plant releases chemicals Bacteria attracted to root Bacteria trigger cell division Infection Nodule formation 8) Nodule has vascular tissue

Nitrogen Cycle All nitrogen fixing is carried out by Nitrogenase Where does all the energy come from? What industrial process achieves this reaction? 16ATP 16 ADP + 16Pi 8 NADH+H + NAD + N 2 2NH 3 + H 2

Nitrogen Cycle All nitrogen fixing is carried out by Nitrogenase NH 3 is toxic, bacteria and plant quickly convert it to glutamine. What is glutamine? Why is this a mutualistic relationship? 16ATP 16 ADP + 16Pi 8 NADH+H + NAD + N 2 2NH 3 + H 2 glutamine

The Nitrogen Cycle Nitrogen-fixing bacteria Nitrogen-fixing bacteria in root nodules. Nitrite bacteria Nitrate bacteria

Nitrogen Cycle Nitrifying Bacteria NH 3 dissolves readily in soil water Nitrite bacteria: Nitrosomonas Nitrate bacteria: Nitrobacter Nitrate ions diffuse freely in soil water and are more readily absorbed by plants. What type of reaction do these bacteria carry out? NH 3 + H + NH 4 + 2NH 4 + 3O 2 2NO 2 - + 2H 2 O + 4H + 2NO 2 - + O 2 2NO 3 -

Nitrogen Cycle Nitrifying Bacteria NH 3 dissolves readily in soil water Nitrite bacteria: Nitrosomonas Nitrate bacteria: Nitrobacter Nitrate ions diffuse freely in soil water and are more readily absorbed by plants. What is the link with eutrophication in lakes and rivers? NH 3 + H + NH 4 + 2NH 4 + 3O 2 2NO 2 - + 2H 2 O + 4H + 2NO 2 - + O 2 2NO 3 -

The Nitrogen Cycle Nitrogen-fixing bacteria Nitrogen-fixing bacteria in root nodules. Nitrite bacteria Nitrate bacteria Denitrifying bacteria

Nitrogen Cycle Denitrifying Bacteria Nitrate ions are washed into water table, rivers, lakes and sea. Water logged soil and mud is anaerobic Denitrifying bacteria use NO 3 - as final electron acceptor in electron transport chain. NO 3 - is broken down in N 2 gas, released into atmosphere.

Nitrogen 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 Cycle Nitrogen-fixing bacteria in root nodules. Nitrogen-fixing bacteria Nitrite bacteria Nitrate bacteria Denitrifying bacteria Haber process: fertilisers Lightning

The Nitrogen Cycle What is the relevance of nitrogen fixation in crop rotation? Why is good soil drainage important for gardens and arable land? How can high crop yields be explained in water logged paddy fields?

Fertilisers, Farm Waste and Water Pollution Why do farmers add fertiliser to their fields? 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

Eutrophication “ is the natural enrichment of water bodies with nutrients over time ” (succession) Accelerated eutrophication is caused by man.

Eutrophication Fertiliser is leached from fields by rain Water is rapidly enriched with nutrients Is inorganic or organic fertiliser worse?

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

Eutrophication: Data Interpretation What 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?

Week 11 nutrient cycles

More Related Content

What's hot (20)

Viewers also liked (20)

Similar to Week 11 nutrient cycles (20)

Recently uploaded (20)

Week 11 nutrient cycles

Editor's Notes