Consider the formula for glucose: [tex] C_6H_{12}O_6 [/tex].

In the process of photosynthesis, what supplies the hydrogen [tex] (H) [/tex] used in the formation of glucose?

A. light energy
B. carbon dioxide
C. chlorophyll
D. water



Answer :

During the process of photosynthesis, hydrogen (H) necessary for the formation of glucose ([tex]\(C_6H_{12}O_6\)[/tex]) is supplied by water (H2O). Here is a detailed explanation of how this process works:

1. Photosynthesis Overview: Photosynthesis is the process by which green plants, algae, and certain bacteria convert light energy, usually from the sun, into chemical energy stored in glucose.

2. Reactants in Photosynthesis: The primary reactants in photosynthesis are water (H2O) and carbon dioxide (CO2).

3. Role of Water: Water is absorbed by the plant roots and transported to the leaves where photosynthesis occurs. In the chloroplasts of the plant cells, light energy is used to split water molecules into hydrogen and oxygen atoms.

4. Photolysis: This splitting of water is called photolysis. During photolysis:
- Water molecules (H2O) are split into oxygen (O2), protons (H+), and electrons (e-).
- The electrons are utilized in the light-dependent reactions of photosynthesis.
- The protons (H+) from the water are used to form NADPH, which is then used in the Calvin cycle to synthesize glucose.

5. Formation of Glucose: In the Calvin cycle (light-independent reactions) that takes place in the stroma of the chloroplasts, carbon dioxide (CO2) is fixed and, with the help of NADPH and ATP produced in the light-dependent reactions, glucose is synthesized. The hydrogen atoms from NADPH are incorporated into the glucose molecule.

In summary, the hydrogen used in the formation of glucose during photosynthesis comes from water (H2O). This illustrates the key role of water in the overall photosynthetic process.