Difficulty: Medium
Correct Answer: Folic acid (Vitamin B9)
Explanation:
Introduction / Context:
Vitamins play critical roles as coenzymes in many biochemical reactions in the body. Some vitamins are directly involved in the synthesis of nucleic acids, which are essential for DNA replication, RNA formation, and cell division. This question tests your understanding of which specific vitamin is most closely associated with nucleic acid synthesis and proper growth of rapidly dividing cells.
Given Data / Assumptions:
Concept / Approach:
Folic acid (Vitamin B9) is crucial for the synthesis of nucleotides, the building blocks of DNA and RNA. It participates in one carbon transfer reactions needed for forming purines and thymidylate. A deficiency of folic acid leads to impaired DNA synthesis and manifests as megaloblastic anaemia, where bone marrow cells cannot divide properly. Vitamin B12 also plays an important role in nucleic acid metabolism, but in exam oriented questions, folic acid is typically given as the primary vitamin required for nucleic acid synthesis. Vitamin E acts as an antioxidant, riboflavin and niacin are involved mainly in energy metabolism.
Step-by-Step Solution:
Step 1: Enumerate the main roles of each vitamin in the options.Step 2: Recall that folic acid (Vitamin B9) is required for the synthesis of purine and thymine nucleotides, directly affecting DNA and RNA formation.Step 3: Remember that Vitamin B12 is important for red blood cell formation and interacts with folate metabolism but is not usually singled out as the key nucleic acid synthesis vitamin in basic GK questions.Step 4: Vitamin E functions mainly as an antioxidant protecting cell membranes, not as a central nucleic acid coenzyme.Step 5: Riboflavin and niacin are components of FAD and NAD coenzymes in energy metabolism, not primarily in DNA synthesis.Step 6: Therefore, select folic acid (Vitamin B9) as the correct answer.
Verification / Alternative check:
Medical and nutritional literature consistently states that folate coenzymes are required for the de novo synthesis of nucleotides used in DNA and RNA. Clinical conditions like folate deficiency anaemia emphasise how crucial this vitamin is for rapidly dividing cells in bone marrow. While Vitamin B12 deficiency also disrupts DNA synthesis, standard competitive exam questions about nucleic acid synthesis usually name folic acid as the required vitamin, which confirms our choice.
Why Other Options Are Wrong:
Tocopherol (Vitamin E) is primarily an antioxidant and protects cell membranes from oxidation; it is not mainly involved in nucleotide synthesis.Cyanocobalamin (Vitamin B12) is important for nerve function and red blood cell formation but is usually not singled out alone for nucleic acid synthesis in school level questions.Riboflavin (Vitamin B2) functions in redox reactions as part of FAD and FMN coenzymes, not specifically in nucleotide formation.Niacin (Vitamin B3) forms part of NAD and NADP, which are crucial in energy metabolism pathways but not directly highlighted for nucleic acid synthesis.
Common Pitfalls:
Students sometimes confuse the roles of different B vitamins and may select Vitamin B12 or Niacin, thinking all B vitamins equally affect DNA synthesis. Another error is to pick Vitamin E simply because it is well known, without considering its function. To avoid such mistakes, remember the key association: folic acid is indispensable for nucleotide formation and is therefore the vitamin most directly required for nucleic acid synthesis.
Final Answer:
The correct answer is Folic acid (Vitamin B9).
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