Cellular Respiration

• Cellular Respiration

  Respiration occurs in the mitochondria of the cells in all organisms, all the time.

  
  

  Respiration is the process by which the cell breaks down glucose to produce ATP - Adenosine triphosphate.
• Cellular Respiration

  ATP is the ‘energy’ molecule that is used to fuel all the chemical reactions of the cell, including:

  • Active transport of substances across membranes
  • Synthesis of molecules
  • Movement, e.g. phagocytosis, action of actin and myosin in muscle contraction
  • Bioluminescence in cells of such animals as glow-worms and fireflies. 
• Cellular Respiration

  word equation: glucose + oxygen → carbon dioxide + water + ATP + heat energy
• Cellular Respiration - Producing Energy

  The breakdown of glucose may be anaerobic (no oxygen present) or aerobic (oxygen present).

  
  

  ATP is constantly made in cells from ADP - adenosine diphosphate. The energy from respiration adds a high-energy phosphate bond to ADP, making it an ATP molecule.
• Factors Affecting the Rate of Cellular Respiration

  The rate of respiration is determined by factors such as temperature and energy demands.
• Factors Affecting the Rate of Respiration

  Temperature - Increasing the temperature increases the rate of respiration to a certain point (optimum temperature). If temperatures rise too much above the optimum temperature, the enzymes controlling the reaction denature and the reaction no longer takes place.

  
• Factors Affecting the Rate of Cellular Respiration

  Energy demands - The rate of respiration will increase to a maximum rate as the energy demand from the cells of tissues increases. For examples, muscle cells of legs when a human sprints.

  
  

  As the amount of O2 needed and CO2 produced increases, the breathing rate increases to compensate.