Question

What is the role of various raw materials in photosynthesis?

Answer 1

1. Photosynthesis is the process of generating glucose by using inorganic molecules.
2. Water (H₂O) and carbon dioxide (CO₂) are the raw materials for this process.
3. This process generally occurs in the leaves of green plants that contain chlorophyll pigment.
4. The role of chlorophyll is to absorb solar energy and use it for the occurrence of photosynthetic reactions.
5. The overall reaction of photosynthesis is:

$6{\mathrm{CO}}_2+6{\mathrm{H}}_2\mathrm{O}\underset{\mathrm{Sunlight}}{\overset{\mathrm{Chlorophyll}}{\to }}{\mathrm{C}}_6{\mathrm{H}}_{12}{\mathrm{O}}_6+6{\mathrm{O}}_2$

The raw materials of photosynthesis are utilized in the following manner:

1. Splitting of water to release oxygen

1. This reaction is called Hill’s reaction, and it is a light-dependent reaction.
2. This step involves the role of light (photo) and chemicals; thus, it is also called the photochemical phase of photosynthesis.
3. In this step, light energy is absorbed by chlorophyll and utilized to split the water molecules. This leads to the conversion of light energy into chemical energy.
4. The spitting of water releases oxygen (${\mathrm{O}}_2$) and electrons (${\mathrm{e}}^{-}$).
5. ${\mathrm{H}}_2\mathrm{O}\stackrel{\mathrm{Sunlight}}{\to }2{\mathrm{H}}^{+}+\frac{1}{2}{\mathrm{O}}_2+2{\mathrm{e}}^{-}$

2. Fixation of carbon dioxide to form glucose

1. This is the second phase of photosynthesis which is light-independent.
2. The carbon dioxide molecules are reduced to form carbohydrate/glucose molecules (C₆H₁₂O₆) during this reaction.
3. ${\mathrm{CO}}_2\to {\mathrm{C}}_6{\mathrm{H}}_{12}{\mathrm{O}}_6$