Many of the relationships between organisms in nature are those of dependence. Whether it be a deer breathing oxygen produced by a nearby tree or a tick sucking the blood of its unsuspecting host, every organism depends on another organism in some way. [pic]
Molecules and Cells
• Photosynthesis and Cellular Respiration
[pic]Photosynthesis is the process by which autotrophs convert solar energy into the chemical bond energy of glucose (C6H12O6). 6CO2 + 12H2O + solar energy -------> C6H12O6 + 6H2O + 6O2 [pic]Cellular respiration is the process by which autotrophs and heterotrophs convert the chemical bond energy of glucose into the usable bond energy of ATP. Aerobic Cellular Respiration
C6H12O6 + 6O2 -------> 6CO2 + 6H2O + 38 ATP Anaerobic Cellular Respiration
C6H12O6 -------> 2 EtOH + 2CO2 + 2 ATP (Alcoholic Fermentation) C6H12O6 -------> 2 Lactic Acid + 2 ATP (Lactic Acid Fermentation) The oxygen by-product of photosynthesis is used in aerobic cellular respiration by all aerobic organisms. Carbon dioxide (CO2) is released following aerobic cellular respiration and alcoholic fermentation (one form of anaerobic cellular respiration) and is then used by autotrophs during photosynthesis. Thus, these are reciprocal processes. Glucose is produced by autotrophs during photosynthesis. Both autotrophs and heterotrophs break down the glucose to form ATP during cellular respiration. Energy, therefore, is transferred between the autotrophic and heterotrophic levels. Autotrophs are dependent upon heterotrophs only for CO2. All heterotrophs are dependent, either directly or indirectly, on autotrophs for energy, but only aerobic heterotrophs are dependent on autotrophs for oxygen (O2.) [pic] • Enzymes and Substrates
[pic]The rate at which a reaction...