Which precipitates at 50 to 60-degree C but disappears on heating?
**Core Concept**
The question tests the student's knowledge of **protein denaturation** and **coagulation**. It involves understanding how certain proteins behave when exposed to heat, specifically the phenomenon of heat precipitation.
**Why the Correct Answer is Right**
The correct answer is related to the **Hussain-Thierfelder phenomenon**, where a specific protein precipitates at temperatures between 50 to 60 degrees Celsius but redissolves upon further heating. This behavior is characteristic of certain proteins that undergo **reversible denaturation**.
**Why Each Wrong Option is Incorrect**
**Option A:** This choice is incorrect because it doesn't exhibit the specific heat precipitation behavior described.
**Option B:** Similarly, this option does not match the characteristics of the protein in question.
**Option C:** This choice is also incorrect as it doesn't align with the Hussain-Thierfelder phenomenon.
**Clinical Pearl / High-Yield Fact**
A key point to remember is that some proteins can exhibit unusual behavior when exposed to heat, including precipitation and subsequent redissolution. Recognizing these patterns can aid in diagnosing and understanding various clinical conditions.
**Correct Answer:** D. Bence-Jones protein.