Q1) Choose the correct combinations of labeling the carbohydrate molecule involved in the Calvin cycle.
(a) (i) RuBP (ii) Triose phosphate (iii) PGA
(b) (i) PGA (ii) RuBP (iii) Hexose phosphate
(c) (i) PGA (ii) Triose Phosphate (iii) RuBP
(d) (i) RuBP (ii) PGA (iii) Hexose phosphate
Dark reaction – Photosynthesis
- Also, known as the C3 cycle as the 1st stable compound produced is a 3C compound Phosphoglyceric acid (PGA).
- Occurs in the chloroplast of mesophyll cells.
- Initial acceptor of CO2 is a 5C compound Ribulose bisphosphate (RuBP).
- Carboxylation occurs with the help of Rubisco enzyme.
6RuBP + 6CO2 →12 3-PGA.
- Reduction: ATP & NADPH produced during light reaction are used to convert PGA to Glyceraldehyde-3-phosphate (G3P).
12 3-PGA + 12 ATP + 12NADPH → 12G3P + 12ADP + 12iP + 12NADP+.
- Formation of glucose: by using 2 molecules of G3P.
- Regeneration of 6RuBP: by using10 molecules of G3P & 6ATP
Photosynthesis is a process by which chlorophyll-containing cells synthesize carbohydrate from carbon dioxide & water with the help of solar energy & the byproduct is oxygen. It occurs in the Chloroplast. During the light reaction, light energy is converted into chemical energy in the form of ATP & NADPH. This ATP & NADPH is used in the dark reaction to fix CO2 in the stroma. Photophosphorylation occurs in the thylakoids (grana) & involves Photosystem I & II. A Photosystem is a group of closely associated pigments molecules that help in converting solar energy into chemical energy. Also referred as Light-harvesting complexes. It is of 2 types, Non- Cyclic & Cyclic.