Energy and ATP

• What is the structure of ATP?

  It is described as a nucleotide derivative. One ribose sugar, one adenine nitrogenous base, three phosphate groups. The third phosphate group is joined by an unstable, high energy bond.
• How does ATP release energy?

  The unstable bond between the third phosphate group has low activation energy, and, so, is easily broken. Breaking bonds releases lots of energy
• What is the reaction to make ADP?

  Hydrolysis reaction, catalysed by ATP hydrolase (ATPase)

  ATP + H20 -> ADP + Pi + energy

  Adenosine triphosphate + Water -> Adenosine diphosphate + Inorganic phosphate group + energy
• What is the reaction to make ATP?

  Condensation reaction, catalysed by ATP synthase

  ADP + Pi -> ATP + H20

  Adenosine diphosphate + Inorganic phosphate group -> Adenosine triphosphate + Water
• What is phosphorylation?

  When an inorganic phosphate group bonds to a different compound. This transfers energy and makes the compound more reactive.
• Is the synthesis of ATP reversible?

  Yes
• What are the 5 good properties of ATP?

  1. Immediate energy source: releases small, manageable amounts of energy. Wastes less - stops cells from overheating from wasted heat energy
  2. Small and soluble: easily transported
  3. Only one bond needs to be hydrolysed: glucose requires several
  4. Can transfer energy via phosphate: glucose cannot
  5. Cannot pass out of a cell (cannot diffuse and has no protein carriers): each cell has its own constant supply
• What are the 3 poor properties of ATP?

  1. Unstable bonds means ATP is not a long-term energy store
  2. Only exists as a few seconds worth of supply
  3. Cannot be stored - it must be continuously made in the mitochondria
• What are the 4 uses of ATP explained, as well as 3 extra uses?

  1. Metabolic processes - ATP provides energy for polymerisation
  2. Movement - ATP provides energy for muscle contraction
  3. Active transport - requires energy from ATP
  4. Secretion - e.g. ATP needed to form lysosomes
  5. Maintenance, repair and division of cells
  6. Maintenance of body temperature
  7. Bioluminescence