Which of the following glucose transporter is insulin-dependent?

Options

A. GLUT-I
B. GLUT II
C. GLUT III
D. GLUT IV

Answer

To determine which glucose transporter is insulin-dependent, we can follow these steps:

### Step 1: Understand the Types of Glucose Transporters
There are several types of glucose transporters (GLUT) in the human body, each with different characteristics. The main ones mentioned in the question are GLUT 1, GLUT 2, GLUT 3, and GLUT 4.

**Hint:** Remember that glucose transporters can be classified based on their dependence on insulin.

### Step 2: Analyze GLUT 1
GLUT 1 is known to be insulin-independent. It is widely distributed across various tissues, including the brain and red blood cells, and facilitates the transport of glucose regardless of insulin levels.

**Hint:** Identify the characteristics of GLUT 1 and its role in glucose transport.

### Step 3: Analyze GLUT 2
GLUT 2 is also insulin-independent. It primarily functions in the liver, pancreas, and intestines, playing a role in glucose sensing and transport but does not require insulin for its activity.

**Hint:** Consider the tissues where GLUT 2 is active and its mechanism of action.

### Step 4: Analyze GLUT 3
GLUT 3 is primarily found in neurons and is also insulin-independent. It has a high affinity for glucose, allowing it to transport glucose effectively in the brain, but again, it does not depend on insulin.

**Hint:** Focus on the role of GLUT 3 in the nervous system and its independence from insulin.

### Step 5: Analyze GLUT 4
GLUT 4 is the only insulin-dependent glucose transporter among the options provided. It is primarily located in muscle and adipose (fat) tissues. In response to insulin, GLUT 4 translocates to the cell membrane, allowing glucose to enter the cells.

**Hint:** Remember that GLUT 4's activity is directly linked to insulin levels and its role in glucose uptake during anabolic conditions.

### Conclusion
Based on the analysis, the glucose transporter that is insulin-dependent is **GLUT 4**.

**Final Answer:** GLUT 4