Cellular Respiration Aerobic Anaerobic Respiration Respiration

Cellular Respiration  Respiration is the slow controlled release of energy from food.  The energy released is used to fuel all metabolic activities in the organism.  The process takes place in many steps all of which is controlled by enzymes.

Aerobic Respiration The process by which glucose is oxidised in many small steps to give carbon dioxide and water.. C 6 H 12 O 6 + 6O 2 6CO 2 + 6H Energy Glucose + Oxygen Carbon + Water + Energy Dioxide ADP + P(Phosphate) + Energy Energy (released) ATP

ADP = Adenosine Di Phosphate ATP = Adenosine Tri Phosphate.. ATP  Is found in all cells  Yields large amounts of energy  Drives the thousands of biological processes needed to sustain life eg. Growth, movement, reproduction.  Green plants use light energy to manufacture ATP as part of the process of Photosynthesis  In Animals, ATP is formed by the breakdown of glucose molecules in respiration

Summary of important events taking place in aerobic respiration 1.Glucose (or fat) is used as a substrate to provide energy 2.Energy is released in a slow, controlled process 3.The energy released is temporarily stored in ATP 4.Oxygen is used in the process 5.Carbon dioxide and water is released

Anaerobic Respiration In anaerobic respiration the food is broken down without oxygen in animals to form lactic acid and ethanol in plants and yeast.  Lactic acid build up is toxic in animals and needs to be broken down. It usually builds up during strenuous exercise when oxygen is short (Oxygen debt). Plants and Yeast ethyl alcohol + Carbon Dioxide + Energy 2C 2 H 5 OH + 2 CO 2 Glucose C 6 H 12 O 6 AnimalsLactic acid + Energy 2C 3 H 6 O 3

Oxygen Debt  This occurs when the lungs cannot supply all the oxygen that the muscles need eg. During vigorous exercise.  In such a situation the muscles can continue to break down glucose to liberate energy for a short time using anaerobic respiration  This produces lactic acid  At certain levels in the muscles lactic acid causes the sensation of fatigue (tiredness)  Once vigorous exercise stops the accumulated lactic acid must be broken down, this uses up extra oxygen  Panting or Yawning usually allows the body to take in this excess oxygen to ‘pay off’ the oxygen dept

Summary of events taking place in anaerobic respiration 1.No oxygen is used 2.Little energy is produced 3.Alcohol and carbon dioxide are produced by plants and yeast 4.Only lactic acid is produced by animals

Industrial & Domestic Applications of Anaerobic Respiration  Fermentation.  Yeast uses sugar as food and makes ethanol as a by product of the reaction. Ethanol is found in beers, wine and sprits like whiskey and rum.  Fermentation of bacteria (lactobacillus) in the production of yogurt and cheese  Baking.  The carbon dioxide produced by yeast is what makes bread, pastries and cakes light and fluffy

Site of Cellular Respiration Site of cellular respiration Diagrams of Mitochondria found in all eukaryotic cells

Mitochondria  An Organelle found in cells  Contains enzymes responsible for energy production during aerobic respiration  Found in both plant and animal cells