In C 3 plants, the first stable product formed after CO 2 fixation by rubisco is:

Glucose, a 6-carbon compound under most conditions studied

Malic acid, a 4-carbon compound in most observed cases

Oxaloacetate, a 4-carbon compound in standard reference material

In C 3 plants, the first stable product formed after CO 2 fi… - Answer & Explanation

Answer: 3-phosphoglycerate (PGA), a 3-carbon compound.

A Glucose, a 6-carbon compound under most conditions studied
B Malic acid, a 4-carbon compound in most observed cases
C Oxaloacetate, a 4-carbon compound in standard reference material
D 3-phosphoglycerate (PGA), a 3-carbon compound

Correct answer: D. 3-phosphoglycerate (PGA), a 3-carbon compound

Explanation: In C<sub>3</sub> plants, rubisco fixes CO<sub>2</sub> onto RuBP to form an unstable 6-carbon intermediate that immediately splits into two molecules of 3-phosphoglyceric acid (PGA), a 3-carbon compound.

Simplified photosynthesis diagram: light energy, CO₂, and H₂O enter the leaf and are converted in the chloroplast into glucose and O₂.

Concept context

Light reactions, the Calvin cycle, C 3 /C 4 /CAM pathways, photorespiration, and factors affecting the rate of photosynthesis. One of the highest-yield NEET chapters.

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In C<sub>3</sub> plants, the first stable product formed after CO<sub>2</sub> fixation by rubisco is:

Concept context

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