The Process of Photosynthesis (HL IB Biology)

• Simple, inorganic compounds are converted into complex organic ones by photosynthesis
  • The energy required is provided by light
• Photosynthesis occurs in autotrophic organisms such as plants, algae and cyanobacteria
• Photosynthesis is a form of energy conversion, from light energy to chemical energy, stored in biomass
• Energy is stored within the bonds of these organic compounds and provides most of the chemical energy needed for life processes in ecosystems

• During photosynthesis, carbon dioxide is converted to glucose using hydrogen released when a water molecule is split
  • Oxygen is released as a waste product
• The reactants of photosynthesis are carbon dioxide and water
• The products of photosynthesis are glucose and oxygen

Reactants and products of photosynthesis diagram

Photosynthesis as it takes place in a leaf

• We can represent this chemical reaction in a word equation

Photosynthesis word equation

A word equation to represent photosynthesis

• Photosynthesis is carried out in plants, algae and cyanobacteria
• The oxygen that is released comes from the water splitting process which also provides hydrogen to allow the synthesis of glucose
• The paths of the oxygen and hydrogen can be seen more clearly when looking at the chemical symbol equation for photosynthesis

Chemical symbol equation for photosynthesis