Chapter 24 Part 2 Flashcards
What are the 6 essential elements?
1) carbon
2) hydrogen
3) nitrogen
4) phosphorus
5) oxygen
6) sulfur
Why is recycling of elements essential to life on earth?
Recycling of elements is needed for new life forms to continuously emerge
What are the 5 general qualities of biogeochemical cycles?
1) elements originate from non-living reservoirs
2) elements cycle between the abiotic and biotic environments
3) recycling is necessary to maintain balance of nutrients
4) cycles depend on a variety of organisms, including producers, consumers, and decomposers
5) although all organisms participate in recycling, only microorganisms are capable of converting organic compounds into inorganic compounds
Which element accounts for over half of the dry weight of living organisms?
Carbon
What are the primary chemical reactions that cycle carbon?
Photosynthesis, respiration, and fermentation
In reference to carbon, how are photosynthesis, respiration, and fermentation related to one another?
CO2 is the primary reactant for photosynthesis (input) and the product (output) for respiration and fermentation.
What types of organisms are the primary photosynthesizers on earth?
Plants, algae, and Cyanobacteria
By how much has the concentration of CO2 (in ppm) increased in the atmosphere since the industrial revolution?
280ppm to over 409 ppm or 40%
What other atmospheric gas contributes to the greenhouse effect?
Methane (CH4)
How much more effective at trapping heat is methane?
20x more effective
What types of animals contribute 20% to this greenhouse gas?
Cows, goats, sheep
What is the largest reservoir of nitrogen on earth?
The air
What percent of the atmosphere is made up of oxygen?
20%
Why is nitrogen essential for living organisms?
Essential for living organisms to synthesize nucleotides and amino acids
Why is it that the majority of nitrogen on earth cannot be utilized by most organisms?
Most of it is in the form of N2 and it cannot be absorbed and incorporated into amino acids and nucleotides
