Cellular respiration

• Cellular Respiration:

  • Cellular respiration is a chemical process that commonly uses glucose to produce energy
  • Occurs in every cell's cytosol and in the mitochondria
  • Glucose + Oxygen → Carbon Dioxide + Water + Energy
  • ATP (Adenosine Triphosphate) is an energy carrier in all living cells and is created during cellular respiration
  • ATP contains three phosphate groups joined together by high energy bonds
  • When energy is needed, the bonds in ATP are broken and one phosphate group is lost to form ADP (Adenosine Diphosphate), releasing chemical energy
• Energy Requirement of Metabolism:

  • Metabolism is the entirety of biochemical reactions occurring within cells
  • Autotrophs can produce energy by using sunlight via photosynthesis
  • Heterotrophs must obtain energy from glucose as they cannot carry out photosynthesis
  • Oxygen and glucose are reactants, while Glucose is the product of cellular respiration
• Structure of Mitochondria:

  • Mitochondria contain an outer membrane, a folded inner membrane, and cristae
  • The inner membrane contains many folds called cristae, increasing the surface area for cellular respiration
  • Cellular respiration occurs in the matrix and inner membrane/cristae
• Aerobic Respiration:

  • Uses oxygen to break down glucose to produce energy
  • Occurs in 3 stages: Glycolysis (2 ATP), Krebs Cycle (2 ATP), Electron Transport Chain (26 or 28 ATP)
  • Produces 30 or 32 ATP per glucose molecule
  • Factors affecting aerobic respiration include the amount of oxygen present, glucose availability, and temperature
• Anaerobic Respiration:

  • Occurs when oxygen is absent or in limited supply
  • Lactic Acid Fermentation occurs in animals/people: Glucose → Lactic Acid + Energy
  • Alcoholic Fermentation occurs in yeast, bacteria, and plants: Glucose → Ethanol + Carbon Dioxide + Energy
  • Occurs in 2 stages: Glycolysis (2 ATP), Fermentation (0 ATP)
• Overall Equation for Cellular Respiration:

  • Glucose + Oxygen → Carbon Dioxide + Water + Energy
  • Two types of cellular respiration: Aerobic (with oxygen) and Anaerobic (without oxygen)
  • Aerobic respiration produces 30 or 32 ATP per glucose molecule, while Anaerobic respiration produces only 2 ATP per glucose molecule