The Process of Photosynthesis (DP IB Biology)

Transformation of Light Energy During Photosynthesis

• 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

Conversion of Carbon Dioxide to Glucose

• 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

Release of Oxygen

• 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