Cellular respiration is the ability of a cell of an organism to metabolize chemicals into the production of adenosine triphosphate (ATP), the cell's primary energy molecule. There are two forms of cellular respiration. Chemotrophic respiration, used by animals, and phototrophic respiration (aka photosynthesis) used by plants and fungi. Chemotrophic respiration requires oxygen to efficiently make ATP and releases carbon dioxide as a waste product. Photosynthesis requires carbon dioxide and releases oxygen as a waste product. A closer look at these two types of breathing will show why these processes are related and how they differ. Photosynthesis is the process by which plants/fungi convert light photons and carbon dioxide into energy in the form of ATP and NADPH. This energy is then connected to the Calvin cycle and the biosynthesis of starch and sucrose. Photosynthesis is mainly synthesized in the chloroplast of the cell. The chloroplast is made up of three membranes that help organize and regulate photosynthesis by creating specialized regions for the metabolic pathway to produce products and reactants. The inner membrane contains the stroma. The stroma contains thylakoids and enzymes specific to the glycolate pathway. The thylakoid is made up of a stack of grana and these grana are interconnected. These stacks of thylakoid layers together form a semi-permeable light to light photons and constitute the proton gradient which allows the synthesis of ATP. The absorption of light in the form of photons across the thylakoid membrane into light is the first step in photosynthesis. These photons absorbed through light undergo photochemical reduction in which they are absorbed into pigments such as chlorine...... middle of paper ...... the metabolism of these molecules is spontaneous and does not require light to start. Photosynthesis requires chlorophyll to be present to process light and at the same time depends on light, so it would not occur without one or both. It is obvious that they both rely on each other, without photosynthesis to produce the oxygen that the chemotrophs breathe to metabolize glucose for energy. Works cited1. Hardin, J., Bertoni, G., Kleinsmith, LJ, & Becker, WM (2012). Becker's cellular world. Boston: Benjamin Cummings.2. Photosynthesis vs Respiration – Difference and Comparison | Different. (nd). Retrieved from http://www.diffen.com/difference/Photosynthesis_vs_Respiration.3. Mueller-Cajar, Oliver et al. “Structure and function of the AAA+ Cbbx protein, a red-type Rubisco Activase.” Nature 479.7372 (2011): 194-199. MEDLINE. Internet. April 17. 2014.