Cellular RespirationRespiration is the transfer of stored energy in food molecules to a more usable form.Respiration involves the exchange of gases between the organism and the environment.Cellular respiration involves a series of enzyme-controlled reactions in which energy in food is broken down into energy that the organism can use (ATP).This energy is the energy used by the body to carry out the life functions.ATP = Adenosine Triphosphate = 3 Phosphates
When ATP is broken down, energy is released, and a phosphate is lost, and ADP is formed.
ADP = Adenosine Diphosphate = 2 PhosphatesWater + ATP ADP + P + EnergyThis is called Hydrolysis.
Dehydration Synthesis is the reverse of hydrolysis.
Dehydrate means to remove water.ADP + P + EnergyWater + ATPThere are two types of respiration: Anaerobic and AerobicAnaerobic respiration is when the organism does not use oxygen.
Aerobic respiration is when the organism uses free oxygen to carry out respiration.
The majority of organisms carry out aerobic respiration.
Anaerobic RespirationAlso called Fermentation or GlycolysisSome cells lack the enzymes necessary for anaerobic respiration, while others revert to anaerobic respiration when oxygen is lacking.The enzymes needed for anaerobic respiration are found in the cytoplasm.Glucose is broken down in a series of enzyme controlled reactions into either lactic acid or alcohol and carbon dioxide.Lactic acid is produced in animals and causes muscle fatigue.Lactic acid is also produced by some bacteria and is important in making cheeses, buttermilk, and yogurt.Alcohol and CO2 are produced by yeast and bacteria and are important in brewing and baking. Anaerobic Respiration produces 2 ATP OnlyGlucose(enzymes) 2 Lactic Acids + 2 ATPGlucose(enzymes) 2 Alcohol + 2 CO2 + 2 ATPOR
Aerobic RespirationOxygen is used during aerobic respiration.Aerobic respiration takes place in the mitochondria.During this process, and due to the presence of oxygen, the chemical energy of glucose is released gradually in a series of enzyme-controlled reactions (Krebs Cycle).Aerobic Respiration is more efficient because more ATP energy is created at the end.If oxygen is present after anaerobic respiration, then aerobic respiration can occur. Pyruvic Acid is the intermediate substance produced in both alcohol and lactic acid fermentation, before aerobic respiration take place.C6H12O6 + 6 02 6 H2O + 6 CO2 + 36 ATPGlucose + OxygenWater + Carbon Dioxide + Energy
Comparing Photosynthesis to Cellular RespirationThey are basically the opposite. Photosynthesis produces sugar and oxygen needed for life functions. Cellular Respiration uses oxygen and sugar to produce Carbon Dioxide and Water. Only plants use Photosynthesis.
PhotosynthesisCellular RespirationIn ChloroplastsIn MitochondriaCO2 + H2O = C6H12O6 + O2O2 + C6H12O6 = CO2 + H2O