1. The essential elements mentioned above are cycled through cells and the earth in biogeochemical cycles (the carbon, nitrogen, and sulfur cycles.) Select the correct answer or fill in the blanks to summarize these cycles:
a. Carbon dioxide is taken in from the atmosphere by [autotrophs/heterotrophs] and converted to glucose through the process of carbon _______________. When heterotrophs eat autotrophs they use catabolism to break down glucose to make ATP and waste carbon is released as _______________.
b. There is plenty of nitrogen available in the atmosphere but it is not accessible to organisms because it is in the form of Nitrogen gas (N2). N2 is fixed by [bacteria/plants/animals] and converted to ammonia (NH3.) NH3 can be used by [bacteria/plants/animals] to build their cells. Next, by consuming food with amino acids, [bacteria/plants/animals] can get access to nitrogen for their own cellular needs.
c. There is also a good quantity of sulfur in dirt, rocks, and the atmosphere. Sulfur cycles between H2S => S0 => SO4 => SH groups in Proteins => back to H2S. Using _______________ respiration, anoxygenic photosynthesis, and chemolithoautotrophy [bacteria/plants/animals] convert H2S and S0 to SO4 which is taken in by [bacteria/plants/animals] and used to build their cells. When [bacteria/plants/animals] eat plants they take in essential amino acids containing sulfur and recycle these to make their proteins.