Question

Decide if each of the following characteristics applies best to peptide hormones (P), steroid hormones (S), both classes (B), or neither class (N).

are lipophobic and must use a signal transduction system

have a short half-life, measured in minutes

often have a lag time of 90 minutes before effects are noticeable

are water-soluble, and thus easily dissolve in the extracellular fluid for transport

most hormones belong to this class

are all derived from cholesterol

consist of three or more amino acids linked together

are released into the blood to travel to a distant target organ

are transported in the blood bound to protein carrier molecules

are all lipophilic, so diffuse easily across membranes

Answer 1

Peptide hormones are water-soluble and lipophobic with short half-lives, requiring membrane-bound receptors for action, while steroid hormones are lipid-soluble, have longer half-lives, and can directly enter cells to interact with intracellular receptors.

Step-by-step explanation:

The classification of hormones can be a complex topic, taking into account their solubility, structure, and mechanism of action in the body. Peptide hormones are water-soluble and lipophobic, meaning they can't diffuse through the lipid bilayer of cell membranes and must utilize membrane-bound receptors and signal transduction systems to exert their effects. They tend to have short half-lives, often measured in minutes, due to their rapid breakdown and excretion. In contrast, steroid hormones are lipid-soluble (lipophilic) and can cross cell membranes directly to interact with intracellular receptors.

Derived from cholesterol, these hormones usually exhibit longer half-lives and often travel in the bloodstream bound to protein carriers. The lag time before observable effects can be seen is often associated with steroid hormones due to the time needed for gene transcription and subsequent protein synthesis, which can take around 90 minutes or more.