- 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
- ADP+Pi+free energy→ATP+H2O
- ATP production increases in low pH cuz provides more H+ (energy)