Question

The discussion for this week will focus on the importance of the two main topics of this chapter (photosynthesis and cellular respiration) to each other. There is a unique balance between these two energy cycles, and your postings should address something specific that addresses this idea. For instance, you can focus on one of the following: the history of these processes (which one we think started first and how that eventually led to the other one), different types of interactions, how other things affect them (poisons, temperatures, global climate, etc.), where the organisms are that perform these processes, which organisms have them, the different parts of each one of these and how they are related or how they came about, or the fact that there are cycles involved and what that may indicate. I need an outside source with this with in paragraph citation as well as a reference citing at the end..

Answer 1

During the course of evolution, two major processes that have been evolved with oxidation of the environment are photosynthesis and aerobic respiration. There remains a debated about the prior onset of either of the processes. However, evolutionary records and evidences from molecular biology show that photosynthesis remains the primary process. Photosynthesis is not only based upon the utilization of aerobic carbon dioxide as a source of carbon, but can also be performed by using other inorganic sourcs for energy, such as sulphur, methane etc. This is evidence by the sulphur-reducing bacteria and methanogenic bacteria in the environment. Hence, these organisms refer to the initial ones on the planet which started photosynthesis and slowly turned the environment more oxygenic in nature.

By the course of evolution, mutualism and endosymbiosis developed and flourished leading to generation of complex cells, as the first eukaryotic cells. These eukaryotic as well as plant cells tend to perform aerobic respiration as well as photosynthesis since they required more energy for survival and simultaneously were able to fix gaseous carbon dioxide into usable chemical form. The gaseous oxygen so released in this process not only turned the atmosphere more habitable, but also aided in aerobic respiration. This complex cycle is still continued in the atmosphere and a delicate balance is maintained between the carbon release and carbon uptake.

Consequently, the global climate, temperature and gaseous toxins are kept check upon by these green plants as they are able to utilize them as their primary organic or inorganic source of energy.