Adenosine Triphosphate, or ATP, is a nucleotide used for storing energy in organic molecules. Nucleotides are organic molecules made up of a sugar molecule, phosphate unit and nitrogenous base. They are the building blocks of nucleic acids like DNA and RNA. DNA and RNA, in turn, are the building blocks of all known organic life.
The generation of ATP is crucial for organic life, as it acts as a currency for various reactions. When an organism wants to do some form of work, such as move muscles, it uses sucrose to perform the task, but ATP is used in the formation of sucrose. Energy is stored in the phosphate bonds of the molecule using a covalent bond. Organic cells break the bond, releasing energy and turning the ATP to ADP (adenosine diphosphate). Mitochondria in cells then reattach a phosphate unit to the molecule, effectively recycling the ATP.
German chemist Karl Lohmann first discovered ATP in 1929, where he called it "inosinic acid" after isolating the nucleotide from muscle and liver extracts. German-American biochemist Fritz Lippmann determined that ATP was the main energy delivery mechanism for cells between 1939 and 1941. It was Lippmann who coined the phrase "energy-rich phosphate bonds" to describe ATP.