Final answer:
A hormone molecule performs its function by binding to its receptor on the target cell and triggering a chain of events that lead to the target cell's response. This can include stimulation of protein synthesis and alteration in cell activity. Hormones can mediate changes directly by binding to intracellular receptors or indirectly by binding to cell surface receptors and stimulating signaling pathways.
Step-by-step explanation:
A hormone molecule performs its function by binding to its receptor on the target cell, which triggers a chain of events leading to the target cell's response. This response can include the stimulation of protein synthesis, activation or deactivation of enzymes, alteration in the permeability of the cell membrane, altered rates of mitosis and cell growth, and stimulation of the secretion of products.
For example, steroid hormones easily diffuse through the cell membrane and bind to intracellular receptors in the cytosol or nucleus. The hormone-receptor complex then enters the nucleus and binds to the target gene on the DNA. This triggers the transcription of the gene, resulting in the formation of mRNA. The transcribed mRNA is then translated into proteins that alter cell activity.
Overall, hormones can mediate changes directly by binding to intracellular receptors and modulating gene expression (transcription and translation) or indirectly by binding to cell surface receptors and stimulating signaling pathways.