Chapter 13 Photosynthesis
The relationship between photosynthesis and respiration
The products of photosynthesis, glucose and oxygen, can be used as reactants in respiration to
synthesise ATP.
The products of respiration, carbon dioxide and water, can then be used as reactants in
photosynthesis.
Photosynthesis
Photosynthesis captures light energy to make glucose from carbon dioxide and water.
Overall photosynthesis equation:
6CO2 + 6H2O + light energy → C6H12O6 + 6O2
Respiration
Cellular respiration breaks down respiratory substrates like glucose, releasing energy that is
temporarily stored in the form of ATP.
Overall respiration equation:
C6H12O6 + 6O2 → 6CO2 + 6H2O + energy
Key stages of photosynthesis
There are three main stages in photosynthesis:
1. Capturing of light energy - This is done by pigments such as chlorophyll.
2. The light-dependent reaction - This is when light energy is converted into chemical energy.
3. The light-independent reaction - This is when sugars and other organic molecules are
produced.
The relationship between photosynthesis and respiration
The products of photosynthesis, glucose and oxygen, can be used as reactants in respiration to
synthesise ATP.
The products of respiration, carbon dioxide and water, can then be used as reactants in
photosynthesis.
Photosynthesis
Photosynthesis captures light energy to make glucose from carbon dioxide and water.
Overall photosynthesis equation:
6CO2 + 6H2O + light energy → C6H12O6 + 6O2
Respiration
Cellular respiration breaks down respiratory substrates like glucose, releasing energy that is
temporarily stored in the form of ATP.
Overall respiration equation:
C6H12O6 + 6O2 → 6CO2 + 6H2O + energy
Key stages of photosynthesis
There are three main stages in photosynthesis:
1. Capturing of light energy - This is done by pigments such as chlorophyll.
2. The light-dependent reaction - This is when light energy is converted into chemical energy.
3. The light-independent reaction - This is when sugars and other organic molecules are
produced.
