Q73.Match List I with List II
| LIST I | LIST II |
|---|---|
| A. Thiamine pyrophosphate | I. Glycogen phosphorylase |
| B. Pyridoxal phosphate | II. Pyruvate carboxylase |
| C. Biotin | III. Lactate dehydrogenase |
| D. Nicotinamide adenine dinucleotide | IV. Pyruvate dehydrogenase |
Choose the correct answer from the options given below:
(1) A-IV, B-II, C-III, D-I
(2) A-IV, B-I, C-II, D-III
(3) A-I, B-II, C-III, D-IV
(4) A-I, B-III, C-IV, D-II
Thiamine pyrophosphate (TPP), pyridoxal phosphate (PLP), biotin, and NAD are key coenzymes matched to specific enzymes in this biochemistry question. The correct matching identifies their roles in metabolic pathways like decarboxylation and phosphorylation.
Correct Answer
Option (2): A-IV, B-I, C-II, D-III.
Coenzyme-Enzyme Matches
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A. Thiamine pyrophosphate (TPP) pairs with IV. Pyruvate dehydrogenase. TPP, derived from vitamin B1, acts as a coenzyme in oxidative decarboxylation reactions, enabling pyruvate dehydrogenase to convert pyruvate to acetyl-CoA in the link reaction before the Krebs cycle.
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B. Pyridoxal phosphate (PLP) pairs with I. Glycogen phosphorylase. PLP, from vitamin B6, facilitates glycogen breakdown by aiding phosphorolytic cleavage of glucose units from glycogen.
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C. Biotin pairs with II. Pyruvate carboxylase. Biotin serves as a CO2 carrier in carboxylation reactions, essential for pyruvate carboxylase to form oxaloacetate in gluconeogenesis.
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C. Nicotinamide adenine dinucleotide (NAD+) pairs with III. Lactate dehydrogenase. NAD+ accepts electrons in redox reactions, shuttling them as NADH in lactate dehydrogenase during lactate-to-pyruvate conversion.
Option Analysis
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(1) A-IV, B-II, C-III, D-I: Incorrect. PLP does not match pyruvate carboxylase (biotin does), and NAD+ mismatches glycogen phosphorylase.
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(2) A-IV, B-I, C-II, D-III: Correct, as detailed above.
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(3) A-I, B-II, C-III, D-IV: Incorrect. TPP does not act on glycogen phosphorylase (PLP does), and biotin mismatches lactate dehydrogenase.
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(4) A-I, B-III, C-IV, D-II: Incorrect. TPP mismatches glycogen phosphorylase, PLP mismatches lactate dehydrogenase, and biotin mismatches pyruvate dehydrogenase.
Introduction to Coenzyme Matching
In biochemistry exams like NEET or CUET PG, questions on thiamine pyrophosphate pyruvate dehydrogenase match test knowledge of coenzymes and their enzyme partners. These matches reveal how vitamins like B1, B6, and B7 support metabolism—from energy production to glycogen breakdown. Understanding them boosts scores in molecular biology sections.
Roles in Key Pathways
TPP enables pyruvate dehydrogenase to decarboxylate pyruvate, linking glycolysis to the TCA cycle. PLP activates glycogen phosphorylase for glucose release during fasting. Biotin powers pyruvate carboxylase in gluconeogenesis, while NAD+ drives lactate dehydrogenase in anaerobic conditions.
Exam Tips
Focus on vitamin-derived coenzymes: TPP (B1) for decarboxylases, PLP (B6) for phosphorylases/aminotransferases, biotin (B7) for carboxylases, NAD (B3) for dehydrogenases. Practice similar match-the-following questions for retention.
Why This Matters
These pairings are crucial for cellular energy, making them high-yield for competitive exams in life sciences. Master the thiamine pyrophosphate pyruvate dehydrogenase match to ace related queries.
