Final answer:
Peptide hormones have a shorter half-life compared to steroid hormones because they are water-soluble, do not bind to transport proteins, and are not lipid-soluble, which means they must interact with surface receptors and do not accumulate in tissues.
Step-by-step explanation:
The statement that peptide hormones typically have a long half-life is FALSE. The half-life of a hormone refers to the time it takes for the concentration of the hormone to reduce to half its original level. Steroid hormones, which are lipid-derived and not water-soluble, often have a longer half-life as they circulate in the blood while bound to transport proteins. This binding provides a more complex structure, thereby extending the steroid hormones' half-life, unlike peptide hormones that are typically shorter in duration. Examples include the steroid hormone cortisol, with a half-life of approximately 60 to 90 minutes, in contrast to the peptide hormone epinephrine, which only has a half-life of about one minute. Lipid-derived hormones can permeate plasma membranes, allowing them to remain in circulation longer than peptide hormones that need surface receptors to initiate cellular response.
Secreted peptides such as insulin are stored in vesicles until released in response to stimuli. Peptide and protein hormones are water-soluble and need receptors on the surface of target cells because they cannot pass through the plasma membranes due to their lipid insolubility. Such characteristics of peptide hormones mean that they do not accumulate in tissues, reducing the risks caused by their metabolites and contributing to their short half-lives.