Investigative Science 2007-2008 PODs (p. 91) March 31-April 1 Define the following words. You may use a textbook. 1. What is the definition of respiration?

Investigative Science 2007-2008

PODs (p. 91)March 31-April 1

Define the following words. You may use a textbook.

1. What is the definition of respiration?

2. What is the definition of denitrification?

3. What is the definition of combustion?


Carbon and Nitrogen Cycles

Matter is neither created nor destroyed…. Therefore it has to cycle around the Earth.


Carbon is always on the move

Carbon is an element. It is part of oceans, air, rocks, soil and all

living things. Carbon doesn’t stay in one place. It is

always on the move!


Carbon Cycle Reservoirs

Atmosphere: Carbon is stored as Carbon Dioxide

Living things: All living things on Earth are made up of Carbon.

Fossils: Carbon can be transformed into fossil fuels if buried for long periods of time

Rocks: Carbon is a major component of rocks. Limestone for example is made of Calcium Carbonate.

Oceans: Carbon can freely move in between the oceans and atmosphere. It is used to make shells, coral and other components of the ocean.


Processes of the Carbon Cycle

Photosynthesis: The process of plants taking carbon dioxide (CO2) out of the atmosphere and converting it into oxygen (O2) 6CO2 + 6H2O C6H12O6 + 6O2

C6H12O6 is a sugar called glucose Within the plant a process called

cellular respiration converts glucose into ATP (energy) ATP stands for Adenosine Triphosphate. Large amounts of energy are stored in the chemical bonds. When they are broken they release energy that can be used!



Respiration: The process of releasing Carbon Dioxide back to the atmosphere. C6H12O6 + 6O2 → 6CO2 + 6H2O +

ATP Respiration occurs in both plants

and animals. When we breathe we inhale

oxygen and exhale carbon dioxide!


What’s Glucose?

Glucose, C6H12O6, is a simple sugar. Can you answer the following questions about it?

1. How many atoms of carbon does glucose have? Hydrogen? Oxygen?

2. How many atoms does glucose have in total?

3. How many molecules of glucose does respiration use?


Processes of the Carbon Cycle Consumption: When animals eat

plants carbon passes from plants to animals. The only way animals get carbon is through eating it.

Decay/Decomposition: When animals die. Decay releases carbon. Animal remains can also be transformed into fossil fuels if they are buried long enough.

Refining: Crude fossil fuels are refined into useable forms of fuel such as gasoline.

Combustion: When fossil fuels are burned they release carbon dioxide back to the atmosphere.



Exchange with Oceans: carbon dioxide can freely move between the atmosphere and the ocean. The oceans are one of the largest sinks (reservoirs) for carbon.

Release from forest fires: When trees in the forest are burned carbon is released into the atmosphere


What do you think?

Carbon naturally cycles around the earth dynamically. Humans can influence and change some parts of the cycle, such as combustion and forest fires. What does human influence mean for the

future earth?


The Carbon Cycle Game

http://www.windows.ucar.edu/earth/climate/carbon_cycle.html


PODs (p.94)April 2-3

1. Glucose is a ________ and has the formula C6H12O6

2. ATP is a form of _________.

3. ATP is created during the process of _______________.

4. The ______ is the driving energy force of the water cycle.


The Nitrogen Cycle

Nitrogen is an element. A member of the halogen family.

It is found in living things like plants and animals.

It is also an important part of non-living things like the air above and the dirt below.

Atoms of nitrogen don't just stay in one place. They move slowly between living things, dead things, the air, soil and water.

These movements are called the nitrogen cycle.


Nitrogen Cycle Reservoirs

Atmosphere: Approximately 80% of the molecules in Earth's atmosphere are made of two nitrogen atoms bonded together (N2).

Living Things: All plants and animals need nitrogen to make amino acids, proteins and DNA, but the nitrogen in the atmosphere is not in a form that they can use.

Genetic Material: Nitrogen (N) is an essential component of DNA, RNA, and proteins, the building blocks of life.


Processes of the Nitrogen Cycle

Nitrogen Fixation: By bacteria: Plants and animals

cannot take nitrogen directly out of the atmosphere. Therefore, it must be fixed, or taken out of the atmosphere, by bacteria. These bacteria live in symbiosis with legumes, a simple nut like dried fruit within the soil.

By lightning, forest fires and hot lava flows: These events fixate small amount of nitrogen. The energy is enough to break the bonds that hold two nitrogen atoms together and free up nitrogen for other chemical processes.



Nitrogen Uptake: Nitrogen is usually quickly incorporated into protein and other organic nitrogen compounds, either by a host plant, the bacteria itself, or another soil organism. When organisms nearer the top of the food chain (like us!) eat, we are using nitrogen that has been fixed initially by nitrogen fixing bacteria.



Denitrification: The loss or removal of nitrogen or nitrogen compounds; specifically: reduction of nitrates or nitrites commonly by bacteria (as in soil) that usually results in the escape of nitrogen into the air.



Decay: When organisms die, their bodies decompose bringing the nitrogen into soil on land or into ocean water. Bacteria alter the nitrogen into a form that plants are able to use. Other types of bacteria are able to change nitrogen dissolved in waterways into a form that allows it to return to the atmosphere.


Impacts of Humans

Certain actions of humans are causing changes to the nitrogen cycle and the amount of nitrogen that is stored in the land, water, air, and organisms.

The use of nitrogen-rich fertilizers can add too much nitrogen in nearby waterways as the fertilizer washes into streams and ponds.

The waste associated with livestock farming also adds large amounts of nitrogen into soil and water. The increased nitrate levels cause plants to grow rapidly until they use up the supply and die.


The Nitrogen Cycle

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Investigative Science 2007-2008 PODs (p. 91) March 31-April 1 Define the following words. You may use a textbook. 1. What is the definition of respiration?