ATP

• Principle molecule for storing and transferring energy for cell work and activation energy; converted by enzymes

Structure

• Basically RNA adenine nucleotide with two more phosphates                                                     
• Nitrogenous base (adenine) attached
• Ribose sugar (carbohydrate)
• Three phosphate groups
  • All negatively charged groups → VERY unstable/reactive → has lots of potential energy

ATP Hydrolysis

• Releases free energy (-) by hydrolyzing the last (terminal) phosphate group
• Inorganic phosphate used to add molecule that has phosphate
• Powers cellular work:
  • Chemical Work – making chemical bonds                                                                                 
  • Transport Work – transporting materials in/out cells
  • Mechanical Work – physical movement (e.g. muscle contractions)

ATP Function

• Energy coupling – use exergonic reaction of ATP hydrolysis to power endergonic reactions in the cell

Energy released is linked by shared/phosphorylated intermediate to endergonic reaction

ATP Regeneration

• ATP cannot be made by the body, ATP is converted or recycled in the body
• ATP Dehydration Synthesis: Net ATP made by phosphorylation when ADP combines with phosphate group using energy from molecule (ex: glucose)
  • ADP+Pi+free energy→ATP+H2O
    • Cycle recycles ADP and inorganic phosphate
• ATP production increases in low pH cuz provides more H+ (energy)