Full Process Of Photosynthesis:-
Photosynthesis is the process by which green plants, algae, and some bacteria convert light energy into chemical energy stored in glucose. Here’s an overview of the process:
Overall Equation
The general equation for photosynthesis can be represented as:
[ text{6 CO}_2 + text{6 H}_2text{O} + text{light energy} rightarrow text{C}_6text{H}_12text{O}_6 + text{6 O}_2 ]
Stages of Photosynthesis
1. Light-Dependent Reactions
These occur in the thylakoid membranes of the chloroplasts and require light to produce ATP and NADPH.
– Photon Absorption: Chlorophyll and other pigments absorb light, exciting electrons to a higher energy state.
– Water Splitting: Water molecules are split into oxygen, protons, and electrons (photolysis).
– Electron Transport Chain (ETC): Excited electrons move through the ETC, creating a proton gradient that drives ATP synthesis.
– NADP+ Reduction: Electrons and protons reduce NADP+ to NADPH.
2. Light-Independent Reactions (Calvin Cycle)
These occur in the stroma of the chloroplasts and do not require light directly. They use ATP and NADPH produced in the light-dependent reactions to convert carbon dioxide into glucose.
– Carbon Fixation: CO₂ is attached to a 5-carbon sugar, ribulose bisphosphate (RuBP), by the enzyme RuBisCO, forming 3-phosphoglycerate (3-PGA).
– Reduction Phase: ATP and NADPH are used to convert 3-PGA into glyceraldehyde-3-phosphate (G3P).
– Regeneration of RuBP: Some G3P molecules are used to regenerate RuBP, allowing the cycle to continue.
Summary
Photosynthesis involves capturing light energy to produce ATP and NADPH in the light-dependent reactions and using these molecules to fix carbon dioxide into glucose in the Calvin cycle. This process is vital for converting solar energy into chemical energy, supporting life on Earth by providing food and oxygen.
