Cellular Respiration Aerobic Respiration Anaerobic Respiration Cellular Respiration
Cellular Respiration Aerobic Respiration Anaerobic Respiration
Cellular Respiration Ø Respiration is the slow controlled release of energy from food. Ø The energy released is used to fuel all metabolic activities in the organism. Ø 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 + 6 O 2 Glucose + Oxygen Energy (released) 6 CO 2 + 6 H 20 + Energy Carbon + Water Dioxide + Energy ADP + P(Phosphate) + Energy ATP
ADP = Adenosine Di Phosphate ATP = Adenosine Tri Phosphate. ATP ØIs found in all cells ØYields large amounts of energy ØDrives the thousands of biological processes needed to sustain life eg. Growth, movement, reproduction. ØGreen plants use light energy to manufacture ATP as part of the process of Photosynthesis ØIn 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. ØLactic 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 Glucose C 6 H 12 O 6 Animals ethyl alcohol + Carbon Dioxide + Energy 2 C 2 H 5 OH + 2 CO 2 Lactic acid + Energy 2 C 3 H 6 O 3
Oxygen Debt ØThis occurs when the lungs cannot supply all the oxygen that the muscles need eg. During vigorous exercise. ØIn such a situation the muscles can continue to break down glucose to liberate energy for a short time using anaerobic respiration ØThis produces lactic acid ØAt certain levels in the muscles lactic acid causes the sensation of fatigue (tiredness) ØOnce vigorous exercise stops the accumulated lactic acid must be broken down, this uses up extra oxygen ØPanting 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 ØFermentation. v. 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. v. Fermentation of bacteria (lactobacillus) in the production of yogurt and cheese ØBaking. v. 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 ØAn Organelle found in cells ØContains enzymes responsible for energy production during aerobic respiration ØFound in both plant and animal cells
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