Q5
Write your answer in about 150 words for each of the following : 10×5=50 (a) Fatty acids regulate the nature of lipids, justify. 10 (b) Define coenzyme. Explain the role of coenzymes in the regulation of metabolic reactions by giving suitable examples. 10 (c) Explain the respiratory regulation of acid-base balance. 10 (d) Describe the rapidly acting synaptic transmitters with suitable examples. 10 (e) What is sperm capacitation ? Describe the method of mammalian sperm capacitation in vitro. 10
हिंदी में प्रश्न पढ़ें
निम्नलिखित प्रत्येक के लिए लगभग 150 शब्दों में अपना उत्तर लिखिए : 10×5=50 (a) वसा (लिपिड) की प्रकृति को वसा अम्ल (फैटी एसिड्स) नियंत्रित करते हैं, सिद्ध कीजिए । 10 (b) सहएंजाइम (कोएंजाइम) को परिभाषित कीजिए । उपापचयी अभिक्रियाओं के नियमन में कोएंजाइम की भूमिका की व्याख्या उदाहरण सहित कीजिए । 10 (c) अम्ल-क्षार संतुलन के श्वसन नियमन की व्याख्या कीजिए । 10 (d) तेजी से कार्य करने वाले अंतःप्रदर्शी संचारियों (सायनैप्टिक ट्रांसमिटर्स) का उदाहरणों सहित वर्णन कीजिए । 10 (e) शुक्राणु क्षमतायन (स्पर्म कैपेसिटेशन) क्या है ? पात्रे (इन विट्रो) में स्तनधारी शुक्राणु क्षमतायन विधि का वर्णन कीजिए । 10
Directive word: Justify
This question asks you to justify. The directive word signals the depth of analysis expected, the structure of your answer, and the weight of evidence you must bring.
See our UPSC directive words guide for a full breakdown of how to respond to each command word.
How this answer will be evaluated
Approach
The directive 'justify' in part (a) demands evidence-based reasoning, while parts (b)-(e) require 'explain,' 'describe,' and 'what' responses. Allocate approximately 30 words per sub-part (150 words each, 10 marks each). Structure: for (a) state how fatty acid saturation/chain length determines lipid properties; (b) define coenzyme then illustrate with NAD+/FAD in metabolic regulation; (c) explain CO2-HCO3- buffer system and respiratory compensation; (d) classify neurotransmitters by speed with acetylcholine/norepinephrine examples; (e) define capacitation then outline in vitro methods using Indian livestock models if relevant. No conclusion needed; maintain strict word discipline per part.
Key points expected
- (a) Fatty acid saturation degree (saturated vs. unsaturated) and chain length directly influence lipid melting point, membrane fluidity, and packing density—justify with examples like stearic vs. oleic acid effects on membrane properties
- (b) Coenzyme definition as non-protein organic cofactors; specific roles of NAD+/NADH in dehydrogenase reactions and FAD in succinate dehydrogenase for metabolic flux regulation
- (c) Respiratory regulation via CO2 excretion modulation; Henderson-Hasselbalch equation application; hypoxia/hypercapnia responses and renal compensation interplay
- (d) Rapidly acting transmitters (small molecule, ionotropic): acetylcholine (nicotinic), glutamate (AMPA), GABA-A; contrast with slow neuromodulators
- (e) Sperm capacitation as post-ejaculatory membrane changes enabling acrosome reaction; in vitro methods: swim-up, Percoll gradient, TALP/HTF media with calcium ionophore or heparin induction
- (f) Applied relevance: cryopreservation in Indian cattle breeding (Murrah buffalo semen) and ARTs; clinical acid-base disorders in veterinary practice
Evaluation rubric
| Dimension | Weight | Max marks | Excellent | Average | Poor |
|---|---|---|---|---|---|
| Concept correctness | 20% | 10 | Precise biochemical mechanisms across all parts: correct fatty acid-lipid property relationships; accurate coenzyme-cofactor distinctions; valid respiratory acid-base chemistry; correct synaptic transmission speed classification; accurate capacitation molecular events (cholesterol efflux, tyrosine phosphorylation) | Generally correct concepts with minor errors: vague fatty acid explanations; conflates coenzyme with prosthetic group; oversimplified respiratory regulation; mixes fast/slow transmitter categories; incomplete capacitation definition | Fundamental misconceptions: states fatty acids don't regulate lipids; confuses coenzyme with enzyme; describes renal instead of respiratory regulation; lists hormones as synaptic transmitters; describes capacitation as occurring in epididymis |
| Diagram / labelling | 15% | 7.5 | Clean, labeled diagrams where applicable: membrane lipid packing comparison for (a); coenzyme redox cycling for (b); CO2 transport/bicarbonate buffer schematic for (c); synaptic cleft with receptor types for (d); sperm membrane changes during capacitation for (e) | Basic diagrams with partial labeling or missing key structures; adequate but not exemplary visual communication | No diagrams where clearly needed; messy unlabeled sketches; diagrams that misrepresent structural relationships |
| Examples & nomenclature | 20% | 10 | Specific, accurate examples throughout: palmitic/oleic/linoleic acids for (a); NAD+, FAD, CoA, TPP with specific reactions for (b); acetylcholine, glutamate, GABA with receptor subtypes for (d); TALP, HTF, Sperm-TALP media for (e); Indian context (NDRI Karnal protocols) | Generic examples without specificity; some correct nomenclature with minor errors; missing Indian applied context | Incorrect or missing examples; wrong chemical names; no specific media or receptor types; fabricated examples |
| Process explanation | 25% | 12.5 | Clear stepwise mechanisms: how unsaturation creates kinks affecting membrane fluidity; sequential coenzyme reduction/oxidation in metabolic pathways; CO2-HCO3- equilibrium shifts with ventilation changes; neurotransmitter release-to-action sequence; chronological capacitation events from cholesterol removal to hyperactivation | Processes described but lacking sequential clarity; missing key intermediate steps; conflates cause and effect | No logical process flow; describes outcomes without mechanisms; confused temporal sequences; static descriptions of dynamic processes |
| Evolutionary / applied context | 20% | 10 | Integrates applied significance: membrane fluidity adaptation in poikilotherms for (a); coenzyme evolution and metabolic efficiency; respiratory compensation in high-altitude adaptation; synaptic transmission speed in predator-prey interactions; capacitation relevance to IVF success rates and Indian livestock improvement programs (IVF in cattle, buffalo) | Brief mention of applications without depth; generic statements about importance; missing Indian context | No applied or evolutionary context; purely descriptive answers; misses relevance to animal breeding or veterinary medicine |
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