Due to lack of oxygen, cellular respiration diminishes and anaerobic metabolism predominates. Water is fundamental to photosynthesis and respiration. Refer to (cellular respiration, anaerobic respiration and photosynthesis). Potassium serves as an activator of enzymes used in photosynthesis and respiration. Obligate anaerobes metabolise energy by anaerobic respiration or fermentation. The diaphragm is the main muscle of respiration and functions in breathing. This improves oxygen delivery in the periphery and contributes to the control of respiration. Most of the ATP produced by aerobic cellular respiration is made by oxidative phosphorylation. It is a facultative anaerobe capable of aerobic respiration. They can be mixotrophs, capable of aerobic respiration and fermentation. Copper is essential in the aerobic respiration of all eukaryotes. This requires the expenditure of metabolic energy released from the respiration of root cells. Nutrients used in cellular respiration include carbohydrates, amino acids and fatty acids. ATP ratio resulting from increasing cellular respiration. The rest goes to metabolic processes such as growth, respiration, and reproduction.