Chapter no 13:Respiration and Energy transfer
Respiration and Energy Transfer Biology Respiration and Energy Production – Grade 7 13.1 Formation of ATP ATP (Adenosine Triphosphate) is the energy currency of the cell. The formation of ATP is called phosphorylation . In nature, phosphorylation occurs in three different ways: Photophosphorylation – occurs during photosynthesis. Substrate-level phosphorylation Oxidative phosphorylation Substrate-level phosphorylation is the direct transfer of a phosphate group from a substrate to ADP to form ATP. It occurs in the cytoplasm and in the mitochondrial matrix. Oxidative phosphorylation occurs on the inner mitochondrial membrane. Here, ATP is formed using the energy released during oxidation of NADH+H + and FADH 2 . When energy is required, ATP is broken down (hydrolysed) into ADP and inorganic phosphate, releasing energy for metabolic activities. Respiration is a catabolic process in which complex organic compounds are broken down to release en...