Question

The process by which protein and proteinaceous compounds are decomposed into amino acids or amines is known as

• A. Aminisation
• B. Amonification
• C. Immobilisation
• D. Nitrification

Hint:

Remember the flow: Protein $\rightarrow$ Amine (Aminisation) $\rightarrow$ Ammonia (Ammonification).
Both together are called Mineralization.
Microbes do this to get carbon for energy, releasing "waste" nitrogen in the process!

Answer 1

The Correct Option is A

Step 1: Understanding the Question:
The question asks to name the specific first step in the mineralization of organic nitrogen, where complex proteins are broken down into simpler amino compounds.
Detailed Explanation:

• Mineralization Sequence:
Organic N (Proteins) $\rightarrow$ Amino Acids/Amines $\rightarrow$ Ammonia ($NH_3$/$NH_4^+$) $\rightarrow$ Nitrite $\rightarrow$ Nitrate.

• Aminization (Step 1):
Soil microbes (heterotrophs) produce extracellular enzymes (proteases) to break down large protein molecules into amines and amino acids. This specific step is called Aminisation.

• Ammonification (Step 2):
The amino acids are then further broken down by a wide variety of microbes to release Ammonia. This is called Ammonification.

• Other Options:
Immobilization: The opposite of mineralization; microbes take up inorganic N to build their own bodies.
Nitrification: The conversion of Ammonium to Nitrate by Nitrosomonas and Nitrobacter.

Step 2: Final Answer:
The conversion of proteins to amino acids/amines is termed Aminisation.