All of the following hormones have cell surface receptors except –
**Core Concept**
Steroid hormones, such as cortisol and aldosterone, typically exert their effects by diffusing across the cell membrane and binding to intracellular receptors, which then activate transcription factors to regulate gene expression. In contrast, peptide hormones and catecholamines typically bind to cell surface receptors, triggering various signaling cascades within the cell.
**Why the Correct Answer is Right**
The correct answer is likely to be a steroid hormone, given that it is the only option listed that does not bind to cell surface receptors. Steroid hormones, such as cortisol and aldosterone, are lipid-soluble and can diffuse across the cell membrane to bind to intracellular receptors, such as the glucocorticoid receptor (GR) or the mineralocorticoid receptor (MR). This allows them to regulate gene expression and exert their effects on the cell.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because it is likely a peptide hormone, such as insulin or growth hormone, which binds to cell surface receptors to activate signaling pathways.
**Option B:** This option is incorrect because it is likely a catecholamine, such as epinephrine or norepinephrine, which binds to cell surface receptors, such as adrenergic receptors, to activate signaling pathways.
**Option D:** This option is incorrect because it is likely a hormone that binds to cell surface receptors, such as thyroid-stimulating hormone (TSH) or follicle-stimulating hormone (FSH).
**Clinical Pearl / High-Yield Fact**
It's essential to remember that steroid hormones, such as cortisol and aldosterone, have different mechanisms of action compared to peptide hormones and catecholamines. While peptide hormones and catecholamines bind to cell surface receptors, steroid hormones can diffuse across the cell membrane to bind to intracellular receptors.
**Correct Answer:** D.