ATP

• Adenosine triphosphate:

  In respiration, the energy released from glucose is used to make ATP.

  ATP is made from the nucleotide base adenine, ribose sugar and THREE phosphate groups. = Knows as a nucleotide derivative as it is a modified form of a nucleotide.
• Once ATP is made, it diffuses to the part of the cell requiring energy. Energy in ATP is stored in high energy bonds between the phosphate groups and released via hydrolysis.
• Making and using ATP

  • When energy is needed by a cell, ATP is broken down into ADP (Adenosine DIphosphate) and Pi (inorganic phosphate). This is a hydrolysis reaction. A phosphate bond is broken and energy is released, this reaction is catalysed by the enzyme ATP hydrolase.
  • The release inorganic phosphate can be added to another compound to make it more reactive, this is phosphorylation.
  • ATP can be synthesised via a condensation reaction between ADP and Pi, this happens during respiration and photosynthesis and is catalysed by the enzyme ATP synthase.