Respiration

• Respiration


  Process that transfers energy from glucose to release energy that living cells use to function
• Majority of energy used by living organisms comes from molecules of glucose originally made by plants during photosynthesis
• Cellular respiration

  1. Exothermic reaction that transfers energy from glucose

  2. Continuously occurring in living cells

  3. Involves breaking apart glucose molecules to release energy
• How organisms use energy

  • Building up larger molecules from smaller ones (e.g. amino acids to form proteins)
  • Muscular contraction for movement
  • Maintaining body temperature
• Most reactions in cells are catalyzed by enzymes
• Metabolism

  All the chemical processes that occur within a living organism to maintain life
• Aerobic respiration


  • More common type
  • Takes place whenever there is enough oxygen
  • Most efficient way to transfer energy from glucose
  • Takes place continuously in plants and animals
  • Occurs in mitochondria
• Aerobic respiration

  Glucose + Oxygen → Carbon dioxide + Water
• Aerobic respiration equation is the opposite of photosynthesis equation
• Anaerobic respiration

  • Respiration without oxygen
  • Used when not enough oxygen available (e.g. sprinting)
  • Incomplete breakdown of glucose
  • Produces lactic acid
• Anaerobic respiration

  Glucose → Lactic acid
• Anaerobic respiration in plants and yeast

  • Glucose converted to ethanol and carbon dioxide instead of lactic acid
  • Used in industry to make bread, beer, and wine
• Anaerobic respiration in plants and yeast

  Glucose → Ethanol + Carbon dioxide