C1.2 Cellular Respiration

• what is ATP?


  ATP is the energy currency of the cell
• • Respiration begins in the cytoplasm

  1. Glucose is converted into pyruvate and yields 2ATP2. Pyruvate is oxidized & decarboxylated, producing 1CO2 molecule each, & reducing NAD+ to NADH3. In the presence of oxygen, pyruvate is further converted into CO2, H2O and more ATP4. In the absence of oxygen, pyruvate is further converted into other chemicals, and does not yield any more ATP
• Biochemical processes that require ATP as an energy source

  • Biosynthesis - Assembly of organic polymers (macromolecules) requires ATP hydrolysis
  • Anabolic reactions use ATP to construct complex molecules from simpler subunits
  • Active transport - ATP is required to move material against a concentration gradient
  • Nerves utilise ATP to establish a resting potential prior to generating a nervous impulse
  • Vesicular transport (endocytosis / exocytosis) requires ATP to break and reform membranes
  • Movement - The movement of cell components or the whole cell is dependent on ATP
  • Chromosomes are segregated during mitosis and meiosis in an energy-dependent process
  • The contraction of muscle cells (via the shortening of sarcomeres) involves the use of energy
• What distinguishes aerobic respiration from anaerobic respiration in humans

  Mitochondria are only used in respiration