SYNOPSIS

• Cellular respiration is the mechanism of oxidative break down of food materials within the cell to release energy and the trapping of this energy for the synthesis of ATP.
  
  
• Glycolysis is the common pathway seen in both aerobic and anaerobic respiration.
  
  
  

• The net gain of ATP during glycolysis is 4 ATP + 6 ATP = 10 ATP − 2 ATP = 8 ATP
  
  
• Fermentation is the process in which the incomplete break down of glucose takes place in the absence of oxygen.
  
  
• Alcohol Fermentation: Pyruvic acid is decarboxylated into acetaldehyde and carbon dioxide in the presence of the enzymes pyruvate decarboxylase and thiamine pyrophosphate.
  
  
• Lactic Acid Fermentation: Pyruvic acid accepts hydrogen from NADH₂ and forms lactic acid.
  
  
• Tricarboxylic Acid Cycle: Net ATP Gain = 30 molecules
  
  
• Total Yield of ATP from Respiration = 36 ATP
  
  
  
  
  
• Electron Transport System
  
  

• Synthesis of ATP from ADP and inorganic phosphates in mitochondria with the help of ATP synthetase is called oxidative phosphorylation.

• Processes which involve breakdown and synthesis of substances, i.e. catabolism and anabolism, are called amphibolic pathways. 

• The ratio of the volume of CO₂ evolved to the volume of O₂ consumed in respiration is called the respiratory quotient.