Biology pt2 respiration

• Respiration


  A chemical reaction that releases energy from glucose (sugar)
• Respiration is something that all living organisms have in common
• Respiration is necessary for living organisms to keep functioning
• Respiration is a chemical reaction

  1. Old substances get changed into new ones

  2. Reactants are the old substances

  3. Products are the new substances
• Respiration happens in every cell of every living organism
• The energy released by respiration is used for all the other chemical reactions that keep you alive
• Aerobic respiration


  Respiration using oxygen, takes place in the mitochondria of animal and plant cells
• Aerobic respiration


  1. Glucose and oxygen react to produce carbon dioxide and water

  2. This reaction releases lots of energy
• Word equation for aerobic respiration

  Glucose + oxygen → carbon dioxide + water + energy
• Anaerobic respiration


  Respiration without oxygen, less efficient than aerobic respiration
• Anaerobic respiration usually only happens when cells can't get enough oxygen
• Anaerobic respiration in humans


  • When you exercise hard, your body can't always get enough oxygen to your muscle cells, so your muscle cells start to respire anaerobically
• Anaerobic respiration in plants

  • If the soil a plant's growing in becomes waterlogged (full of water) there'll be no oxygen available for the roots, so the root cells will have to respire anaerobically
• Plants don't need to eat, they can make their own food using sunlight and substances from the soil and the air
• Photosynthesis


  A chemical process that takes place in green plants, which produces food (glucose) from sunlight, carbon dioxide and water
• Photosynthesis


  Sunlight and chlorophyll are used to convert carbon dioxide and water into glucose and oxygen
• Word equation for photosynthesis

  Carbon dioxide + water → glucose + oxygen
• Leaves


  • Broad surface area for absorbing sunlight
  • Most chloroplasts are found near the top of the leaf where they can get the most light
  • Network of veins deliver water to leaf cells and transport glucose
  • Underside of leaf covered in stomata that allow carbon dioxide to diffuse in and oxygen to diffuse out
  • Air spaces inside leaf allow carbon dioxide to move easily between leaf cells
• Minerals plants need from the soil

  • Nitrogen
  • Potassium
  • Phosphorus
  • Magnesium
• Plants absorb these minerals through their roots (along with water)