Respiration b

• the ultimate source of energy is food and the sun
• humans need energy for growth, cell division and moving molecules and ions against a concentration gradient
• Plants need energy to take up mineral salts from the soil, opening and closing their stomata and transporting food substances
• Animals need energy for movement, sending messages through nerves, transporting things inside the body and keeping warm
• respiration is the chemical process that takes place in every living cell by which energy is released from food, keeping the cell alive
• Glucose + oxygen > carbon dioxide + water + ATP
• the process of oxidation converts carbon to carbon dioxide and hydrogen to water and at the same time sets free energy
• some energy is always lost as heat
• It is in the mitochondria that the chemistry of aerobic respiration takes place
• The mitochondria generate ATP which is used by the cell as a source of energy
• ATP stands for Adenosine Triphosphate
• Catabolism means Break-down reactions
• one molecule of glucose, 36 ATP molecules are released
• Those who respire anaerobically, all their lives and never use oxygen.

  Some anaerobic organisms of this type are poisoned by oxygen
• Those who respire anaerobically only when oxygen is in short supply


  Organisms of this type are poisoned by excessive amounts of ethanol or lactic acid
• Glucose > ethanol + carbon dioxide + little energy 


  C6H12O6 > 2C2H5OH + 2CO2 + little energy
• The sugar is not completely oxidized to carbon dioxide and water but converted to carbon dioxide and alcohol


  This type of fermentation is called alcoholic fermentation
• Only later, is the pyruvic acid completely oxidized to carbon dioxide and water.


  of lactic acid). Only In animals, the first stages of respiration in muscle cells are anaerobic and produce pyruvic acid
• in animals and bacteria: Glucose > lactic acid > CO2 + H2O + ATP
• Brewing and baking. Both processes depend on the fact that yeast undergoes alcoholic fermentation, production ethanol and carbon dioxide.
• Vinegar, produced when a liquid is left to ferment in the presence of bacteria in combination with oxygen to produce vinegar.
• Biogas (methane). The process depends on decay bacteria. First the sewage is pumped into a large tank. Here the solid matter sinks to the bottom, forming a sludge. This is broken down by anaerobic bacteria which give off the gas methane. This can be used as a fuel, supplying power to run the sewage works.
• Silage: The grass is prevented from decaying by lactic acid produced by anaerobic bacteria
• during exercise, pyruvic acid may build up in a muscle faster then it can be oxidized. In this case, it is turned into lactic acid in the muscles and removed in the bloodstream as lactate.


  Lactate is a negatively charged ion coming from lactic acid
• Glucose >   lactic acid + Little energy
• the lactic acid is broken down into carbon dioxide and water in the liver


  The oxygen required to get rid of lactic acid after exercise is called oxygen debt
• The oxygen breathed in reacts with the lactic acid and lactate in order to continue the oxidation reaction thus completing the breakdown of lactic acid into carbon dioxide and water releasing ATP