Respiration

• Cellular respiration


  An exothermic reaction that occurs continuously in the mitochondria of living cells to supply the cells with energy
• Energy released during respiration is needed for

  • Chemical reactions to build larger molecules, for example, making proteins from amino acids
  • Muscle contraction for movement
  • Keeping warm
• Respiration in cells


  • Can take place aerobically (using oxygen)
  • Can take place anaerobically (without oxygen)
• Aerobic respiration


  Complete oxidation of glucose, large amount of energy is released
• Anaerobic respiration


  Incomplete oxidation of glucose, much less energy is released per glucose molecule than in aerobic respiration
• Aerobic respiration


  Glucose + oxygen -> carbon dioxide + water
• Anaerobic respiration in muscles

  Glucose -> lactic acid
• Anaerobic respiration in plant and yeast cells

  Glucose -> ethanol + carbon dioxide
• Fermentation


  Anaerobic respiration in yeast cells
• Products of fermentation


  • Bread
  • Alcoholic drinks
• Anaerobic respiration in plant and yeast cells is represented by the equation: glucose -> ethanol + carbon dioxide
• Typical plant cell


  • Cell wall
  • Cytoplasm (where enzymes are made)
  • Chloroplast
  • Nucleus (holds genetic code for enzymes involved in respiration)
  • Mitochondrion (contains the enzymes for aerobic respiration)
  • Cell membrane (allows gases and water to pass freely into and out of the cell, controls the passage of other molecules)
• During exercise


  Heart rate, breathing rate, and breath volume all increase to supply the muscles with more oxygenated blood
• If insufficient oxygen is supplied

  Anaerobic respiration takes place instead, leading to the build-up of lactic acid
• During long periods of vigorous exercise

  Muscles become fatigued and stop contracting efficiently
• Removal of lactic acid

  1. Lactic acid in the muscles is transported to the liver in the blood

  2. Lactic acid is converted back to glucose
• Metabolism


  The sum of all the reactions in a cell or the body
• Metabolic processes


  • Synthesis and breakdown of carbohydrates
  • Synthesis and breakdown of proteins
  • Synthesis and breakdown of lipids
• Cellular respiration

  An exothermic reaction that occurs continuously in the mitochondria of living cells to supply the cells with energy
• Cellular respiration

  • The energy released during respiration is needed for all living processes, including chemical reactions to build larger molecules, muscle contraction for movement, and keeping warm
• Types of respiration

  • Aerobic (using oxygen)
  • Anaerobic (without oxygen)
• Aerobic respiration

  Glucose + oxygen -> carbon dioxide + water
• Anaerobic respiration in muscles

  Glucose -> lactic acid
• Anaerobic respiration in plant and yeast cells

  Glucose -> ethanol + carbon dioxide
• The products of fermentation are important in the manufacturing of bread and alcoholic drinks
• You need to learn the balanced symbol equations for aerobic and anaerobic respiration
• Typical plant cell

  • Cell wall
  • Chloroplast
  • Cytoplasm (where enzymes are made)
  • Nucleus (holds genetic code for enzymes involved in respiration)
  • Mitochondrion (contains enzymes for aerobic respiration)
  • Cell membrane (allows gases and water to pass freely)
• Typical animal cell

  • Cytoplasm
  • Nucleus
  • Mitochondrion
  • Cell membrane
• During exercise

  Heart rate, breathing rate, and breath volume all increase to supply muscles with more oxygenated blood
• If insufficient oxygen is supplied during exercise

  Anaerobic respiration takes place instead, leading to the build-up of lactic acid
• During long periods of vigorous exercise

  Muscles become fatigued and stop contracting efficiently
• Oxygen debt

  The amount of oxygen needed to react with the lactic acid to remove it from cells after exercise
• Removal of lactic acid after exercise

  1. Lactic acid in the muscles is transported to the liver in the blood

  2. Lactic acid is converted back to glucose
• Metabolism

  The sum of all the reactions in a cell or the body
• Metabolic processes

  • Synthesis and breakdown of carbohydrates, proteins, and lipids