Photosynthesis Earth's atmosphere, and supplies all of the organic compounds and most of the energy necessary for life on Earth. Although photosynthesis is performed differently by different species, the process always begins when energy from light is absorbed by proteins called reaction centres that contain green chlorophyll pigments. In plants, these proteins are held inside organelles called chloroplasts, which are most abundant in leaf cells, while in bacteria they are embedded in the plasma membrane. In these light-dependent reactions, some energy is used to strip electrons from suitable substances, such as water, producing oxygen gas. The hydrogen freed by the splitting
Microbiologically induced calcite precipitation autotrophic production of carbonate obtain carbon from gaseous or dissolved carbon dioxide. These pathways include non-methylotrophic methanogenesis, anoxygenic photosynthesis, and oxygenic photosynthesis. Non-methylotrophic methanogegenesis is carried out by methanogenic archaebacteria, which use CO and H in anaerobiosis to give CH. Two separate and often concurrent heterotrophic pathways that lead to calcium carbonate precipitation may occur, including active and passive carbonatogenesis. During active carbonatogenesis, the carbonate particles are produced by ionic exchanges through the cell membrane by activation of calcium and/or magnesium ionic pumps or channels, probably coupled with carbonate ion production. During passive carbonatogenesis, two metabolic cycles can be involved,