Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Biogeochemical Cycles Water Cycle Water Cycle A. B. C. D. E. F. G Nitrogen Cycle http://www.elmhurst.edu/~chm/onlcourse/chm110/outlines/nitrogencycle.html The main component of the nitrogen cycle starts with the element nitrogen in the air. Two nitrogen oxides are found in the air as a result of interactions with oxygen. Nitrogen will only react with oxygen in the presence of high temperatures and pressures found near lightning bolts and in combustion reactions in power plants or internal combustion engines. Nitric oxide, NO, and nitrogen dioxide, NO2, are formed under these conditions. Eventually nitrogen dioxide may react with water in rain to form nitric acid, HNO3. The nitrates thus formed may be utilized by plants as a nutrient. Nitrogen Cycle http://www.elmhurst.edu/~chm/onlcourse/chm110/outlines/nitrogencycle.html The main component of the nitrogen cycle starts with the element nitrogen in the air. Two nitrogen oxides are found in the air as a result of interactions with oxygen. Nitrogen will only react with oxygen in the presence of high temperatures and pressures found near lightning bolts and in combustion reactions in power plants or internal combustion engines. Nitric oxide, NO, and nitrogen dioxide, NO2, are formed under these conditions. Eventually nitrogen dioxide may react with water in rain to form nitric acid, HNO3. The nitrates thus formed may be utilized by plants as a nutrient. Nitrogen Cycle http://www.elmhurst.edu/~chm/onlcourse/chm110/outlines/nitrogencycle.html Nitrogen in the air becomes a part of biological matter mostly through the actions of bacteria and algae in a process known as nitrogencfixation. Legume plants such as clover, alfalfa, and soybeans form nodules on the roots where nitrogencfixing bacteria take nitrogen from the c air and convert it into ammonia, c NH3. The ammonia is further converted by other bacteria first into nitrite ions, NO2-, and then into nitrate ions, NO3-. Plants utilize the nitrate ions as a nutrient or fertilizer for growth. Nitrogen is incorporate in many amino acids which are further reacted to make proteins. Nitrogen Cycle http://www.elmhurst.edu/~chm/onlcourse/chm110/outlines/nitrogencycle.html Nitrogen in the air becomes a part of biological matter mostly through the actions of bacteria and algae in a process known as nitrogen fixation. Legume plants such as clover, alfalfa, and soybeans form nodules on the roots where nitrogen fixing bacteria take nitrogen from the air and convert it into ammonia, NH3. The ammonia is further converted by other bacteria first into nitrite ions, NO2-, and then into nitrate ions, NO3-. Plants utilize the nitrate ions as a nutrient or fertilizer for growth. Nitrogen is incorporate in many amino acids which are further reacted to make proteins. Nitrogen Cycle http://www.elmhurst.edu/~chm/onlcourse/chm110/outlines/nitrogencycle.html Ammonia is also made through a synthetic process called the Haber Process. Nitrogen and hydrogen are reacted under great pressure and temperature in the presence of a catalyst to make ammonia. Ammonia may be directly applied to farm fields as fertilizer. Ammonia may be further processed with oxygen to make nitric acid. The reaction of ammonia and nitric acid produces ammonium nitrate which may then be used as a fertilizer. Animal wastes when decomposed also return to the earth as nitrates. Nitrogen Cycle http://www.elmhurst.edu/~chm/onlcourse/chm110/outlines/nitrogencycle.html Ammonia is also made through a synthetic process called the Haber Process. Nitrogen and hydrogen are reacted under great pressure and temperature in the presence of a catalyst to make ammonia. Ammonia may be directly applied to farm fields as fertilizer. Ammonia may be further processed with oxygen to make nitric acid. The reaction of ammonia and nitric acid produces ammonium nitrate which may then be used as a fertilizer. Animal wastes when decomposed also return to the earth as nitrates. Nitrogen Cycle To complete the cycle other bacteria in the soil carry out a process known as denitrification which converts nitrates back to nitrogen gas. A side product of this reaction is the production of a gas known as nitrous oxide, N2O. Nitrous oxide, also known as "laughing gas" - mild anesthetic, is also a greenhouse gas which contributes to global warming. http://www.elmhurst.edu/~chm/onlcourse/chm110/outlines/nitrogencycle.html Carbon Cycle Carbon Cycle • 8-1: ATP formation and usage Copyright Pearson Prentice Hall Chemical Energy and ATP • Chemical Energy and ATP • Energy comes in many forms including light, heat, and electricity. • Energy can be stored in chemical compounds, too. Copyright Pearson Prentice Hall Chemical Energy and ATP • An important chemical compound that cells use to store and release energy is adenosine triphosphate, abbreviated ATP. • ATP is used by all types of cells as their basic energy source. Copyright Pearson Prentice Hall Chemical Energy and ATP • ATP consists of: – adenine – ribose (a 5-carbon sugar) – 3 phosphate groups Adenine ATP Ribose Copyright Pearson Prentice Hall 3 Phosphate groups Chemical Energy and ATP • The three phosphate groups are the key to ATP's ability to store and release energy. Copyright Pearson Prentice Hall Chemical Energy and ATP – Storing Energy • ADP has two phosphate groups instead of three. • A cell can store small amounts of energy by adding a phosphate group to ADP. ATP ADP + Adenosine Diphosphate (ADP) + Phosphate Partially charged battery Energy Energy Adenosine Triphosphate (ATP) Fully charged battery Copyright Pearson Prentice Hall Chemical Energy and ATP – Releasing Energy • Energy stored in ATP is released by breaking the chemical bond between the second and third phosphates. 2 Phosphate groups P ADP Copyright Pearson Prentice Hall Chemical Energy and ATP – What is the role of ATP in cellular activities? Copyright Pearson Prentice Hall Chemical Energy and ATP The energy from ATP is needed for many cellular activities, including active transport across cell membranes, protein synthesis and muscle contraction. ATP’s characteristics make it exceptionally useful as the basic energy source of all cells. Copyright Pearson Prentice Hall