• Photosynthesis is an?endothermic?reaction in which energy from sunlight is transferred to the chloroplasts in green plants
  • Green plants use this energy to make the carbohydrate?glucose?from the raw materials?carbon dioxide?and?water
  • At the same time,?oxygen?is made and released as a waste product

   

• Photosynthesis can be defined as?the process by which plants manufacture carbohydrates from raw materials using energy from light
• Plants are
  • Autotrophs?– they can make complex molecules (glucose) from simple molecules (carbon dioxide and water)
  • Producers -?they can make their own food and so are the first organism at the start of all food chains

   

The products of photosynthesis

• Plants use the glucose they make as a?source of energy?in?respiration
• They can also use it to
  • Produce?starch?for storage
  • Synthesise?lipids?for an energy source in seeds
  • To form?cellulose?to make cell walls
  • Produce?amino acids?(used to make proteins) when combined with nitrogen and other mineral ions absorbed by roots

   

The fate of glucose produced in photosynthesis

• Photosynthesis can be summarised in a word equation as shown below:

Word equation for photosynthesis

Where do the reactants come from and where do the products go?

• This equation can also be shown as a?balanced chemical equation
  • Six?carbon dioxide molecules combine with?six?water molecules to make?one?glucose molecule and?six?oxygen molecules

   

The balanced chemical equation for photosynthesis