ATP as a supply of energy

• ATP is produced during respiration by the addition of inorganic phosphate (Pi) to ADP
• the breakdown of glucose in respiration releases the energy needed to phosphorylate ADP
• the hydrolysis or breakdown of ATP releases an inorganic phosphate as well as a small amount of energy which can be used by the cell

  ATP -> ADP + Pi
• the removal of a phosphate group is known as dephosphorylation

  the hydrolysis of ATP is catalysed by the enzyme ATP synthase

  the ADP and inorganic phosphate produced by the hydrolysis of ATP can be recycled to make more ATP

  ADP + Pi -> ATP
• ATP is formed during respiration and can be hydrolysed to release energy for processes such as active transport, muscle contraction, and building new molecules (anabolic reactions)

  ATP can then be regenerated from ADP and phosphate