What Is The Chemical Equation For Photosynthesis? Stages Of Photosynthesis

What is the chemical equation for photosynthesis?

The photosynthetic process is a process plants use to create nutrients for their metabolic processes. Plants use energy from the sun to reduce carbon dioxide to glucose molecules and oxidize water molecules to molecular oxygen.

This is a complex process that occurs in prokaryotic and eukaryotic plant cells. Photosynthesis is a natural process that is necessary for the metabolic processes of plants and the feeding of animals.

In this article, we’ll be taking a look at the chemical formula for photosynthesis and the relationship between photosynthesis and cellular respiration.

What is the chemical equation for photosynthesis?

6CO2 + 6H2O + light energy ———> C6H12O6 + 6O2

In words,

Carbon dioxide + Water + Light energy ———> Glucose + Oxygen

What are the stages of photosynthesis?

The photosynthetic process occurs in two stages: the light-dependent reaction and the Calvin cycle.

The light-dependent reaction

This is the first part of the photosynthetic process. It occurs in the thylakoid membranes of the cytoplasm. As the name implies, it uses chlorophyll (the green pigment in leaves) to absorb energy from the sun and stores it in the chloroplast in the form of ATP.

The reactions in the light reaction are as follows:

12H2O + 12NADP+ + 18ADP + 18Pi + Light ———> 6O2 + 12NADPH + 18ATP

In words,

Water + Nicotinamide adenine dinucleotide phosphate + Adenine diphosphate + Phosphate + Light ———> Oxygen + Nicotinamide adenine dinucleotide phosphate + Adenosine triphosphate

The Calvin cycle

The Calvin cycle or the dark reaction or the light-independent stage. This reaction occurs in the stroma of the chloroplast.

In this stage, the ATP created in the first phase is used to make sugar molecules. The plant uses these sugar molecules to run its metabolic processes. 

The summary of the reactions in this stage is as follows:

3CO2 + 6NADPH + 5H2O + 9ATP ———> C3H5O3-PO32- + 2H+ + 6NADP+ + 9ADP + 8P

In words,

Carbon dioxide + Nicotinamide adenine dinucleotide phosphate + Water + Adenosine triphosphate ———> Glyceraldehyde-3-phosphate + Hydrogen ions + Nicotinamide adenine dinucleotide phosphate + Adenosine diphosphate + Phosphate

What is the relationship between photosynthesis and cellular respiration?

The product of photosynthesis is the reactant in cellular respiration.

In photosynthesis, carbon dioxide and water react (in the presence of light) to yield glucose and oxygen. This glucose and oxygen go into the cellular respiration pathway and are broken down into carbon dioxide and water.

In other words, photosynthesis takes carbon dioxide from the atmosphere and cellular respiration inputs it back.

Also, photosynthesis releases oxygen and cellular respiration uses the oxygen to break down food and produce energy.


What type of chemical reaction is photosynthesis?

Photosynthesis is an endothermic reaction because it must occur in the presence of sunlight. The chlorophyll in the leaves absorbs sunlight and uses the energy to break down glucose.

Where does photosynthesis occur in plant cells?

Photosynthesis occurs in the thylakoid membranes of the chloroplasts of plant cells. Chlorophyll is present in the chloroplasts of the cells in the plant’s leaves.

Are there animals that undergo photosynthesis?

Naturally, animals do not photosynthesize because they are heterotrophs. However, the pea aphid is one pest that can use sunlight to carry out its metabolic processes.


In simple terms and to help you remember, the chemical equation for photosynthesis is the reverse of the chemical equation for cellular respiration.

The differences are: photosynthesis occurs only in plants while cellular respiration occurs in the mitochondria of both plants and animals.

Learn all about carbon fixation that drives photosynthesis.

Thanks for reading.