Significance of Photosynthesis

Photosynthesis is the process by which green plants, in the presence of light combine water and carbon dioxide to form carbohydrates. Oxygen is released as a by product of photosynthesis.

Photosynthesis is represented by the following overall chemical equation:

6CO2 + 12H2O → C6H12O6 + 6H2O + 6O2

In photosynthesis, CO2 is fixed or reduced) to carbohydrates (glucose C6H12O6). Water is split in the presence of light (called photolysis of water) to release O2. O2 released comes from the water molecule and not from CO2.

Significance of Photosynthesis

  1. Green plants possess the green pigment, chlorophyll which can capture, transform, translocate and store energy which is readily available for all forms of life on this planet.
  2. Photosynthesis is a process in which light energy is converted into chemical energy.
  3. Except green plants, no other organism can directly utilize solar energy to synthesize food, hence they are dependent on green plants for their survival.
  4. Green plants which can prepare organic food from simple inorganic elements are called autotrophic while all other organisms which cannot prepare their own food are called heterotrophic.
  5. During photosynthesis, oxygen liberated into the atmosphere makes the environment livable for all aerobic organisms.
  6. Simple carbohydrates produced in photosynthesis are transformed into lipids, proteins, nucleic acids and other organic molecules.
  7. Plants and plant products are the major food sources of almost all organisms on the earth.
  8. Fossil fuels like coal, gas, and oil represent the photosynthetic products of the plants belonging to early geological periods.

Where Does Photosynthesis Occur

Photosynthesis occurs in green parts of the plant, mostly the leaves, sometimes the green stems and floral buds. The leaves contain specialised cells called mesophyll cells which contain the chloroplast - the pigment containing organelle. These are the actual sites for photosynthesis.