1.6 respiration

• respiration


  chemical process that allows living organisms to release the energy stored in glucose in food

  
• which cells respire?

  ALL CELLS!! bacteria, fungi, animal, plant
• general formula for respiration

  glucose + oxygen -> carbon dioxide + water

  
• what do we use respiration for?

  movement, growth, repair, warmth

  
• adenosine triphosphate (ATP)


  made by the energy released in respiration, supplies energy for the processes of movement, growth, repair, warmth

  
• structure of adenosine triphosphate (ATP)

  adenosine-P-P-P

  
• where is the energy stored in adenosine triphosphate (ATP)?

  third (last) bond of P-P

  
• how does energy get released in adenosine triphosphate (ATP)?

  enzymes break apart the third bond containing energy, so it's an enzyme controlled reaction

  
• aerobic respiration


  breakdown of glucose WITH oxygen, occurs in 2 stages (glycolysis + breakdown of pyruvate)

  
• formula for aerobic respiration

  glucose + oxygen -> energy (for ATP) + carbon dioxide + water

  
• stage 1 - glycolysis


  splitting glucose into two molecules of pyruvate, no oxygen is used in glycolysis, energy is released to make 2 ATP, series of enzyme controlled reactions, some energy was used to made the ATP but most energy is in the pyruvate

  
• stage 2 - breakdown of pyruvate


  36 ATP released with 2 pyruvate and oxygen, excess products are carbon dioxide and water, series of enzyme controlled reactions, occurs in mitochondria

  
• fermentation pathway


  breakdown of glucose without oxygen, anaerobic respiration

  
• fermentation pathway in animals


  glucose pyruvate becomes 2 ATP and lactate, reversible process, occurs in low oxygen conditions (e.g, heavy exercise)

  
• lactate


  form of energy, if there's too much lactate build-up, muscles become fatigued

  
• oxygen debt


  lactate build-up in muscles, causing fatigue and less power, so recovery is needed to convert lactate into pyruvate again using oxygen

  
• fermentation pathway in plants and yeast


  glucose pyruvate becomes 2 ATP and pyruvate then pyruvate becomes ethanol and carbon dioxide, irreversible process because carbon dioxide escapes, occurs in low oxygen conditions (e.g, flooded, muddy)