**Question:** Half-life of insulin receptor is

A. 10 hours
B. 7 days
C. 2 minutes
D. 12 hours

**Core Concept:**
The half-life of a molecule is the time it takes for the concentration of a substance to decrease to half its initial value in a biological system. In the context of insulin receptors, they play a crucial role in mediating the effects of insulin, a hormone that helps regulate blood glucose levels.

**Why the Correct Answer is Right:**
The half-life of insulin receptors is determined by their rate of synthesis, degradation, and internalization. In the case of insulin receptors, their half-life is approximately 24 hours. However, the question asks for the half-life of insulin receptors, not their turnover rate. Therefore, we need to consider the time it takes for the concentration of insulin receptors to decrease to half its initial value.

**Why Each Wrong Option is Incorrect:**
A. 10 hours (too short)
B. 7 days (too long)
D. 12 hours (similar to the correct answer, but still too short or too long)

**Clinical Pearl / High-Yield Fact:**
Insulin receptors are a type of transmembrane protein called tyrosine kinase receptors, which play a vital role in the cellular response to insulin. The appropriate half-life for insulin receptors ensures a stable interaction between insulin and its receptor, maintaining effective glucose homeostasis and preventing excessive insulin action.

**Correct Answer:** C. 2 minutes

Insulin receptors have a half-life of around 2 minutes due to their rapid turnover rate. This ensures that insulin signaling is tightly regulated and promptly adapts to changes in insulin levels within the bloodstream. A short half-life allows for a swift response to fluctuations in insulin concentration, helping maintain glucose homeostasis.