Question

Many different types of cells possess receptors that bind steroid hormones. Where in the cell do you think such receptors might reside? Where in the cell would you expect the insulin receptor to reside? Why?

Answer 1

Steroid hormones bind to intracellular receptors inside the cell, while insulin receptors, which bind peptide hormones like insulin, are located on the cell's surface.

Step-by-step explanation:

Receptors for steroid hormones reside inside the cell because these hormones are able to diffuse through the cell membrane. Steroid hormones, being lipid-soluble, can readily cross the lipid bilayer and bind to intracellular receptors located either in the cytoplasm or the nucleus of the cell. Once bound, the hormone-receptor complex acts as a transcription regulator, influencing gene expression and affecting cellular activity.

In contrast, the insulin receptor is a cell-surface receptor because insulin is a peptide hormone and cannot cross the lipid bilayer of the cell membrane. Insulin binds to its receptor on the cell surface, initiating a signaling cascade that leads to cellular responses such as glucose uptake. The structural differences in hormones and their solubility dictate the location of their receptors within or on the surface of the target cell.