Question

Insulin receptor is an example of

• A. Steroid receptors
• B. Serpentine receptors
• C. Adhesion receptors
• D. Receptor enzyme

Hint:

Receptor enzymes, like the insulin receptor, combine ligand binding with enzymatic activity, allowing them to regulate cellular processes through phosphorylation.

Answer 1

The Correct Option is D

Step 1: Understanding the insulin receptor.
The insulin receptor is a receptor tyrosine kinase, which is a type of receptor enzyme. It acts by binding insulin, causing a conformational change that activates its intrinsic kinase activity, leading to the phosphorylation of downstream targets.
Step 2: Analyzing the options.
(1) Steroid receptors: This is incorrect. Steroid receptors are intracellular and bind steroid hormones, but insulin receptors are membrane-bound and function through a different mechanism.
(2) Serpentine receptors: This is incorrect. Serpentine receptors (G-protein coupled receptors) are involved in other signaling pathways, not insulin signaling.
(3) Adhesion receptors: This is incorrect. Adhesion receptors mediate cell-cell and cell-matrix interactions, not insulin signaling.
(4) Receptor enzyme: Correct — The insulin receptor is a receptor enzyme because it has intrinsic enzyme activity (tyrosine kinase) that is activated upon insulin binding.
Step 3: Conclusion.
The correct answer is (4) Receptor enzyme, as the insulin receptor has enzymatic activity that is activated by insulin binding.