cellular respiration

• Mitochondria


  The site of aerobic respiration
• Cellular respiration


  Glucose (C6H12O6) is broken down to H2O and CO2, and produces LOTS of ATP
• Mitochondria


  • Contain the outer membrane which regulates molecules entering and exiting
  • Contain the inner membrane which is folded into cristae to increase surface area for respiration reactions
  • Contain the matrix which is the jelly-like filling with many enzymes and is the site of the Krebs cycle

  
• Role of mitochondria


  To produce ATP, which is used by cells for energy in active transport, protein synthesis, and movement

  
• Cells with high energy demand (e.g. muscle, secretory, sperm) have more mitochondria with more folded cristae to allow more reactions and ATP production

  
• Aerobic respiration


  Glucose + Oxygen → Carbon dioxide + Water (+ ATP + Heat)
• Aerobic respiration


  • Requires oxygen to break down glucose
  • Starts in cytoplasm but mainly occurs in mitochondria
  • Has three stages: Glycolysis, Krebs Cycle, Electron transport chain
• Glycolysis


  Occurs in cytoplasm, breaks down glucose to pyruvate, produces 2 ATP
• Krebs cycle


  Occurs in mitochondrial matrix, breaks down pyruvate to produce CO2 waste and hydrogen atoms
• Electron transport chain


  Occurs on cristae, hydrogen atoms ionised to H+ and their electrons passed between molecules to generate 36 ATP
• Anaerobic respiration


  Takes place in cytoplasm, does not require oxygen, only produces 2 ATP per glucose
• Respiration is an enzyme-mediated process
• Factors affecting respiration rate

  • Temperature
  • pH
  • Concentration of substrates (glucose, oxygen)
  • Inhibitors
  • Demand