1. Photosynthesis & Cellular Respiration
Cycling of Matter
Earth’s Spheres
Water cycle
Photosynthesis & Cellular Respiration
Carbon cycling
Nitrogen cycling
Phosphorus cycling

2. Earth’s 4 spheres Atmosphere (atmos = vapour)
Layer of air about Earth’s surface
Hydrosphere (hydro = water)
all water found on Earth (including ground water)
Biosphere
Living surface of Earth
regions where living organisms exist
Lithosphere (litho = stone)
Hard part of Earth’s surface

3. Earth’s Spheres
Atmosphere
Biosphere
Lithosphere
Hydrosphere

4. How does matter cycle through these 4 spheres?
Water, carbon, nitrogen, phosphorus

5. Water Cycle
Atmosphere
Biosphere
Lithosphere
Hydrosphere

6. Water cycle summarized
Precipitation
Surface runoff, infiltration, percolation
Evaporation & transpiration
Condensation

7. Candle in Jar A burned for 3 minutes
Joseph Priestley (1733–1804) began a series of experiments that would reveal the essential role of air in the growth of green plants.
First Experiment
Candle in Jar A burned for 3 minutes
Candle in jar with mint plant burned for 5 minutes
Why?

8. Second Experiment
Placed mouse in jar without plant and it died
Placed mouse in jar with mint plant and lived for a longer period of time. (eventually died)
Why?

9. Conclusion Plants and animals help each other.
Now scientists know that plants use carbon dioxide and water to make sugar and oxygen is released as sugars are made.
The mouse used oxygen from the plant to break down sugars. When your body breaks down sugar carbon dioxide and water are released.
This process is called cellular respiration

10. Cellular Respiration
Process of converting food energy into chemical energy that can be used by every cell in the organism
(it’s like exchanging Canadian dollars for US currency which is accepted worldwide)
Occurs in the mitochondria

11. Cellular Respiration C6H12O6 + 6O2 → 6CO2 + 6H2O
Summarized in this equation:
Breakdown of food into chemical energy
food is often shown as glucose (C6H12O6), a type of sugar
chemical energy isn’t shown but is known as ATP
requires oxygen
But… where does the food come from?
C6H12O6 + 6O2 → 6CO2 + 6H2O 11

12. Ingestion If you’re an animal, you get food from another organism
Herbivore: ingest plants (e.g. vegetarians)
Carnivore: ingest animals
Omnivore: ingest both plants and animals
If you’re lucky enough to be a plant…
then you can MAKE your own food!!!
through a process called… 12

13. 6H2O + 6CO2 ----------> C6H12O6+ 6O2
Photosynthesis
6H2O + 6CO > C6H12O6+ 6O2
Process of converting light energy into stored food energy
Occurs in chloroplasts of autotrophs

14. Summary
There is a balance between oxygen and carbon dioxide within the biosphere.
Plants provide oxygen and sugars
Animals and plants provide CO2 and water.
Processes of photosynthesis and cellular respiration are complementary not opposite.

16. ? Thought question… Do plants perform cellular respiration?
To answer this question you need to remember what the purpose of cellular respiration is…
Then think about whether plants have to fulfill that purpose… ?

17. Carbon Cycle All living things contain carbon.
Humans receive carbon from the food they eat. Food energy comes from three types of macromolecules: Carbohydrates(spinach, oranges, sugar, bread), Lipids (oil, butter) and Proteins (meat, eggs)
Carbon is recycled through cellular respiration and photosynthesis and this relationship is called the carbon cycle

19. Fast Track Carbon Cycle
Atmospheric CO2 ↓
Photosynthesis in Autotrophs
Digestion in Organisms
Cellular respiration in organisms
The fast-track flow of carbon occurs between inorganic CO2 in the atmosphere and organic macromolecules found in living organisms.

20. Thought question…
Which of the Earth’s spheres does the fast track cycling of carbon take place in?

21. Introducing the Slow Track Carbon Cycle
The fast track cycle is a simple exchange of CO2 and glucose.
The whole carbon cycle is more complex.
Most of the carbon that forms living organisms is not returned to the atmosphere or water by the fast track cycle.
Most carbon is returned as CO2 from body waste and the decay of dead organisms through the slow track cycle.
Why is it called the slow track?… because something delays the cycle, slowing it down.

22. Matter in Ecosystems Inorganic Organic
Does not contain a combination of
C and H.
Examples: CO2 and H2O
Organic
Contain atoms of C, H and sometimes O and N.
Examples: protein, sugar and fats.
Glucose

23. Are the following molecules organic or inorganic?

24. Delays in The Cycle – Inorganic Carbon
Inorganic carbon can be found in 3 main reservoirs:
Atmosphere Ocean Earth’s crust

25. Delays in The Cycle – Inorganic Carbon
Some carbon in CO2 reacts with sea water (H2O) and form CO32- (carbonate ion) or HCO3- (bicarbonate ion)
CO2 + H2O  CO32- + HCO3-
These ions react with calcium (Ca) and form CaCO3 (calcium carbonate)
Ca + CO32-  CaCO3
Ca + HCO3-  CaCO3
Calcium carbonate is also found in shells of shellfish
When shellfish die, their shells (and thus calcium carbonate) end up as layers of sediments at the bottom of the ocean that get crushed and heated and eventually become rock.

26. Delays in The Cycle – Organic Carbon
Organic carbon is also held in the body of living things.
When they die and decompose, the carbon eventually returns to the cycle in inorganic form.

27. Delays in The Cycle – Organic Carbon
In some ecosystems like bogs, there is very little oxygen, so decaying of the organisms’ dead bodies is very slow.
The dead animals and plants remain for many years at the bottom of the bogs.
Over time, more and more sediment piles on top, trapping the decaying organic matter between layers of rocks.
The result is the formation of the fossil fuels and coal which are all forms of carbon.

28. Delays in The Cycle – Organic Carbon
Similar condition can happen at the bottom of the oceans when decaying aquatic animals and plants are trapped under sediments in a low oxygen environment.

29. Delay in The Cycle – Slow Track Cycle
The carbon in the slow track cycle is unavailable until it is released by natural processes such as:
Uplifting
Weathering
Erosion
Carbon is also released through man-made processes like burning of fossil fuels

30. Uplifting
Material that has been “pushed” up from underneath the ground.
Earthquakes
Volcanoes
Events are due to the movement of the Earth’s plates (called plate tectonics)

31. Weathering
weathering is the chemical or physical breakdown of rock material
example of chemical weathering: acid rain
example of physical weathering: frost wedging

32. Erosion
the removal or transportation of material by agents as running water, ice, wind, etc.
Eg. Bryce Canyon in Alaska

33. Human Impacts on the slow-track cycle
Burning of fossil fuels has sped up the slow track carbon cycle
It takes millions of years to form fossil fuels, yet we’re using it up in only hundreds of years
Global Warming
Global warming is the rise in temperature that the Earth experiences
This can be due to the greenhouse effect where certain gases in the atmosphere trap energy from the sun.
Without these gases, heat would escape back into space and Earth’s average temperature would be colder.
Because of how they warm our world, these gases are referred to as greenhouse gases. Some examples include: water vapor, carbon dioxide
Other greenhouse gases on page 8-9 in booklet

35. Slow Track Carbon Cycle
The slow-track flow of carbon stores carbon under water and in the ground in the form of inorganic carbonates and organic fossil fuels. The carbon is released naturally over time. Human impact has unfortunately sped up that process.
Carbonates in rock
Fossil Fuels ↓
Uplifting, weathering, erosion
Burning of fossil fuels
Atmospheric CO2 35

36. N
Nitrogen Cycle
4 steps

37. N
Nitrogen
Nitrogen makes up 79% of the atmosphere and it exists in an unreative form as N2 gas.
Plants and animals require nitrogen to live. Nitrogen is found in molecules such as proteins and DNA.
Organisms can only use nitrogen in the form of nitrate (NO3- ).
The nitrogen cycle converts N2 to NO3- which is incorporated into living things.

38. N Nitrogen cycle The nitrogen cycle has four main phases:
1- Nitrogen-fixation/nitrification (converting N2  NO3-)
Lightning
Nitrogen-fixing bacteria
2- Absorption /uptake (NO3-  organic compounds)
3- Decomposition (N in organic compounds  NO3- )
4- Denitrification (NO3-  N2)

39. Nitrogen Cycle - Overview
Nitrogen-fixation / nitrification
(2 methods)
2. Absorption / Uptake
Organic compounds
(proteins, DNA)
NO3- N2
4. Denitrification
3. Decomposition

40. N
1. Nitrogen fixation
Lightning: Energy from lightning allows N2 and O2 in the air to react with each other to form NO3-.

41. N 1. Nitrogen fixation Nitrogen-fixing bacteria
Bacteria live in the roots of certain plants known as legumes. Legumes are plants that bear seeds in pods.
Examples of legumes: clover, alfalfa, pea, soybeans.
The bacteria are found in bulges called nodules on the roots of the plant.

42. N 1. Nitrogen fixation Bacteria convert N2 to NO3-.
Some of these ions are released into the soil so that the plant can absorb them.
There is a symbiotic relationship between the plant and the bacteria because plants provide bacteria with sugar and bacteria provide plants with nitrate.

43. Advantages of crop rotation Disadvantages of crop rotation
Application
Applications of nitrogen-fixing bacteria: crop rotation
Advantages of crop rotation
Disadvantages of crop rotation
Replenish/increase N in soil so future crops will thrive.
Legume crops sell at a lower market price so there is a short-term loss of income.

44. N 2. Absorption / uptake Absorption /uptake (NO3-  organic compounds)
Nitrate is dissolved in water in the soil.
Plants absorb the nitrate and incorporate it into organic compounds in their body.
Herbivores and omnivores eat plants to obtain nitrogen.

45. N 3. Decomposition Decomposition (N in organic compounds  NO3- )
Waste and dead matter are broken down by a different type of N-fixing bacteria that exists in the soil. This type of bacteria needs Oxygen/O2 to survive and are said to be aerobic.
Nitrogen in organic compounds is converted back to nitrates, forming intermediate molecules in the process:
Organic compounds  NH3 (ammonia)  NO2 (nitrite)  NO3 (nitrate)

46. N 4. Denitrification Denitrification (NO3-  N2)
Denitrification is performed by denitrifying bacteria that are anaerobic, which means that they survive in environments that lack oxygen.
Denitrification returns NO3- ions back to the atmosphere in the form of nitrogen gas.
The conversion of nitrate to nitrogen may result in the production of an intermediate molecule known as nitrite (NO2).
Soil that contains a lot of nitrate will have a lower pH.

47. Nitrogen cycle - Summary
1. Nitrogen fixation
2. Absorption
Organic compounds
(proteins, DNA)
NO3- N2
4. Denitrification
3. Decomposition

48. http://www. biology. ualberta