Cellular Respiration

• All cells require energy to perform essential life processes.
• This energy is used for

  the synthesis of new parts, movement, and other energy-requiring processes in the cell.
• Most of the energy used in the cell is in the form of adenosine triphosphate (ATP). The

  phosphate groups in this molecule are joined by high-energy bonds.
• Alcoholic fermentation in the yeast and

  lactic acid accumulation in the human muscles are examples of anaerobiosis.
• Other food substances like fatty acids and amino acids could also provide energy.
• Fermentation – an enzymatically controlled anaerobic breakdown of an energy-

  rich compound
• However, glucose (C6H12O6) remains to be the major source of energy in living cells
• The generation of carbon dioxide due to respiration will be indicated by changes in

  the bromthymol blue solution, a pH sensitive indicator. In aqueous media, carbon dioxide

  reacts with water to form carbonic acid.
• A highly acidic solution can change the color

  of the bromthymol blue to orange.
• This is accomplished by cellular respiration, which converts food or chemical

  energy into ATP.
• When respiration occurs only in the presence of oxygen, it is referred to as aerobic

  respiration.
• When it occurs in the absence of oxygen, it is anaerobic. Aerobic respiration

  is more efficient in the conversion of food energy into ATP.