Q.21
ICAR AIEEA PG Physical Science 09 July 2023 (Shift 1) Paper
MCQ (Single Correct) +4 −1
English हिन्दी

Which of the following theories are associated with humus formation?
(A) Polyphenol theory
(B) Lignin-protein theory
(C) Chemiosmosis theory
(D) Sugar-amine condensation theory
Choose the correct answer from the options given below:

ह्यूमस निर्माण (Humus formation) से

निम्नलिखित में से कौन से सिद्धांत जुड़े हैं?
(A) पॉलीफेनोल सिद्धांत (Polyphenol theory)
(B) लिग्निन-प्रोटीन सिद्धांत (Lignin-protein theory)
(C) कीमियोस्मॉसिस सिद्धांत (Chemiosmosis theory)
(D) शुगर-एमीन संघनन सिद्धांत (Sugar-amine condensation theory)
नीचे दिए गए विकल्पों में से सही उत्तर चुनें:

EXPLANATION Soil Microbiology, Organic Matter Decomposition, Humus Chemistry, Humic Acids and Soil Enzymes

The classic theories explaining the synthesis of humus (humic substances) from organic matter are:

  • Polyphenol theory (Flaig): Microbes synthesize quinones from polyphenols derived from lignin degradation, which polymerize with amino compounds.
  • Lignin-protein theory (Waksman): Residual modified lignin complexes directly with microbially synthesized proteins.
  • Sugar-amine condensation / Maillard reaction theory: Reducing sugars condense non-enzymatically with amino acids and amines to form brown melanoidins and humus.
    In contrast, Chemiosmosis theory (C) is Peter Mitchell's Nobel prize-winning theory of ATP synthesis across mitochondrial and thylakoid membranes, having nothing to do with humus formation.
Hence, the humus theories are (A), (B), and (D) only.

ह्यूमस निर्माण (Humification) के प्रमुख सिद्धांत:

  • पॉलीफेनोल सिद्धांत (फ्लेग): लिग्निन अपघटन से प्राप्त पॉलीफेनोल क्विनोन में ऑक्सीकृत होकर अमीनो यौगिकों के साथ बहुलीकृत होते हैं।
  • लिग्निन-प्रोटीन सिद्धांत (वाक्समैन): अपघटित लिग्निन और जीवाणु प्रोटीन के संयोजन से ह्यूमस बनता है।
  • शुगर-एमीन संघनन सिद्धांत (मैलार्ड प्रतिक्रिया): शर्करा और अमीनो अम्लों के गैर-एंजाइमी संघनन से मेलानोइडिन और ह्यूमस बनता है।
    कीमियोस्मॉसिस सिद्धांत (C) पीटर मिशेल द्वारा ATP निर्माण (श्वसन/प्रकाश संश्लेषण) के लिए दिया गया सिद्धांत है, इसका ह्यूमस से कोई संबंध नहीं है।
अतः सही उत्तर केवल (A), (B) और (D) है।
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