Which of the following reaction is affected in patients of scurvy?
**Core Concept**
Scurvy is a disease caused by a deficiency in vitamin C (ascorbic acid), leading to impaired collagen synthesis and connective tissue health. The underlying biochemical defect is the inability to convert proline and lysine to hydroxyproline and hydroxylysine, essential for collagen cross-linking.
**Why the Correct Answer is Right**
Vitamin C is a co-factor for the enzyme prolyl hydroxylase and lysyl hydroxylase, which are responsible for the hydroxylation of proline and lysine residues in collagen. Without vitamin C, these enzymes are unable to function properly, resulting in the accumulation of unhydroxylated collagen and the characteristic symptoms of scurvy. This impaired collagen synthesis leads to defective wound healing, bleeding gums, and joint pain.
**Why Each Wrong Option is Incorrect**
* **Option A:** This option is incorrect because scurvy is not primarily related to carbohydrate metabolism.
* **Option B:** This option is incorrect because scurvy is not primarily related to the citric acid cycle.
* **Option C:** This option is incorrect because scurvy is not primarily related to the synthesis of nucleic acids.
**Clinical Pearl / High-Yield Fact**
Scurvy is a classic example of a disease caused by a nutritional deficiency, highlighting the importance of a balanced diet in maintaining optimal health.
**Correct Answer: C.** This reaction is affected in patients of scurvy.