Question

Choose the correct answer from the alternatives given.
Steroid hormones mediate their action by:

• A. activating adenylate cydase
• B. activating gene expression
• C. binding to the surface membrane of the cells
• D. inhibiting an enzyme

Answer 1

The correct option is B activating gene expression

Steroid hormones and thyroid hormones do not bind to the cell surface receptors. Being lipid soluble, these are able to enter the cells and their nuclei and influence the gene action. The hormone binds to the receptors forming a hormone-receptor complex. It binds to the transcription factors that in turn to DNA and a particular gene is activated. Their transcription leads to the synthesis of a specific protein to influence the metabolism of the recipient cell. Thus, the peptide hormones activate existing enzymes in the cell while steroid hormones bring about the synthesis of new enzymes.

So the correct answer is activating gene expression.