Answer: Glutamic acid.
- A Pyruvic acid
- B Oxaloacetic acid
- C Glutamic acid
- D Citric acid
Correct answer: C. Glutamic acid
Explanation: Reductive amination joins ammonia to alpha-ketoglutarate to make glutamic acid (glutamate), a key step in nitrogen assimilation.
Atmospheric N₂ is fixed into ammonia by nitrogen-fixing bacteria (protected from oxygen by leghaemoglobin in root nodules), converted to nitrate via nitrification for plant uptake, and eventually returned to the atmosphere as N₂ via denitrification, completing the cycle.
Concept context
Essential mineral elements, their roles and deficiency symptoms. Nitrogen fixation and soil nutrition.