c1.2 cell respiration

• what does ATP stand for

  adenosine triphosphate
• what is ATP

  a phosphorylated nucleotide
• components of ATP

  ribose sugar

  adenine base

  3 phosphate groups
• breakdown of ATP

  hydrolysis reaction

  ATP to ADP + phosphate

  uses only 1 enzyme - ATPase

  releases energy
• what does ADP stand for

  adenosine diphosphate
• synthesis of ATP

  condensation reaction (water released)

  ADP + phosphate to ATP + H20

  requires energy

  organisms can't build large stores of ATP, so they only make it when needed
• 6 benefits of ATP

  small and soluble

  universal energy currency

  uses one enzyme (ATPase)

  small amount of energy released during hydrolysis

  relatively stable

  recyclable
• explain why ATP being small and soluble is a benefit

  moves easily inside cells and provides short-term store of chemical energy for cells to use
• explain what is meant by ATP being a universal energy currency

  ATP can be used in all organisms for many different reactions and can be reused many times
• explain the benefit of the hydrolysis of ATP only using one enzyme

  hydrolysis of ATP only uses ATPase enzyme meaning the process can be carried out very quickly whenever needed
• explain the benefit of the energy released during hydrolysis of ATP

  a small and manageable amount of energy is released during the hydrolysis of ATP meaning there is sufficient energy for vital reactions without unnecessary waste
• explain the benefit of the stability of ATP

  ATP is relatively stable at cellular pH levels, meaning it won't break down unless ATPase catalyst is present
• explain the benefit of ATP being recyclable

  ATP hydrolysis is a reversible reaction, meaning the same molecules can be reused elsewhere in the cell for different reactions
• life processes which use ATP (4)

  transporting substances across membranes

  anabolic reactions

  movement

  maintaining body temperature
• examples of ATP uses in transporting substances across membranes

  active transport uses sodium-potassium pump in cell membranes

  exocytosis of digested bacteria from white blood cells
• examples of ATP uses in anabolic reactions

  synthesis of DNA from nucleotides

  synthesis of proteins from amino acids
• examples of ATP uses in movement

  cellular movement of chromosomes via spindle

  mechanical contraction of muscles
• where is ATP used to maintain body temperature

  only in mammals and birds
• respiratory substrates used for aerobic cell respiration

  mainly glucose

  when glucose used up, the cell can continue respiration using other carbohydrates, lipids or proteins as the substrate

  amino acids (proteins) are respired last because they often have essential functions elsewhere in the cell

  the amount of energy released during respiration depends on the substrate being broken down