Question

Mention the main steps in the process of photosynthesis. Explain in BRIEF about each step.

Answer 1

Photosynthesis:

Photosynthesis is an autotrophic mode of nutrition in plants and some bacteria. Photosynthesis is the chemical process by which plants convert light energy into chemical energy to form carbohydrates from simple inorganic substances like atmospheric carbon dioxide and water.

Basic raw materials for photosynthesis:

Photosynthesis requires carbon dioxide, sunlight, water and chlorophyll as its basic raw materials.

Steps of Photosynthesis:

a) Sunlight activates chlorophyll which leads to splitting of the water molecule.
b) The hydrogen released by the splitting of the water molecule is utilised for reduction of carbon dioxide to produce carbohydrates.
c) Oxygen is the by-product of photosynthesis.
d) Carbohydrate is subsequently converted into starch and is stored in the leaves and other storage parts.
e) The splitting of water molecules is part of the light reaction.
f) Other steps are part of the dark reaction during photosynthesis.
Overall reaction of photosynthesis
6CO2+12H2OLightEnergyandChlorophyll→C6H12O6+6O2+6H2O
g) Oxygen is derived from H₂O through photolysis of water.
h) Carbohydrate is formed from the carbon of CO₂.