Energy and ATP

• Energy can be changed from one form to another
• Energy cannot be created or destroyed
• Energy is measured in joules
• ATP stands for adenosine triphosphate
• ATP is made from an adenine, a ribose sugar and 3 phosphate groups
• Adenosine diphosphate (ADP) has two phosphate groups attached to it
• The energy stored in the bonds between the phosphates in ATP is released when they are broken during cellular respiration
• Inorganic phosphates are released when the third phosphate group is removed from ADP
• When ATP breaks down into ADP + Pi, energy is released
• Phosphorylation is the process whereby a molecule gains a phosphate group
• ATP + water = ADP + Pi

  • process required ATP hydrolase
  • hydrolysis reaction
  • releases energy
• ADP + Pi = ATP + water

  • condensation reaction
  • requires energy
  • occurs in respiration and photosynthesis
• 1 glucose makes 38 ATP
• Glucose stores a lot of energy and is released via a long series of reactions so takes longer to release it
• Use of energy

  • metabolism
  • movement
  • active transport
  • metabolic processes
  • secretion
• Activation of molecules

  • inorganic phosphate released during hydrolysis of ATP can phosphorylate other compounds in order to make them more reactive
  • lowers activation energy
• Metabolic processes

  • building of macromolecules
• Active transport

  • energy required to move molecules against the concentration gradient
• Inorganic ions = atom or group of atoms that have acquired a net electric charge by gaining or losing electrons