Respiration and metabolism

• Respiration


  The process of transferring energy from the breakdown of glucose (sugar)
• Respiration is not breathing in and breathing out
• Respiration is the process of transferring energy from the breakdown of glucose (sugar) and it goes on in every cell in your body continuously
• Respiration happens in plants too. All living things respire. It's how they transfer energy from their food to their cells
• Respiration


  The process of TRANSFERRING ENERGY FROM GLUCOSE
• Respiration is exothermic - it transfers energy to the environment
• Examples of how organisms use the energy transferred by respiration


  • To build up larger molecules from smaller ones
  • In animals it's used to allow the muscles to contract (so they can move about)
  • In mammals and birds the energy is used to keep their body temperature steady in colder surroundings
• Aerobic respiration


  The most efficient way of transferring energy from glucose
• Aerobic respiration


  Glucose + oxygen -> carbon dioxide + water + energy
• Anaerobic respiration


  Respiration that occurs without oxygen
• Anaerobic respiration produces lactic acid
• Metabolism


  All the chemical reactions in an organism
• In a cell there are lots of chemical reactions happening all the time, which are controlled by enzymes
• Reactions to make larger molecules from smaller ones


  1. Glucose molecules joined together to form starch, glycogen, cellulose

  2. Lipid molecules made from glycerol and fatty acids

  3. Glucose combined with nitrate ions to make amino acids, then proteins
• Reactions to break down larger molecules into smaller ones

  1. Glucose broken down in respiration

  2. Excess protein broken down to produce urea
• The sum of all the reactions that happen in a cell or the body is called its metabolism