aminoohormone

An amino hormone is a type of hormone that is derived from a single amino acid. Despite their simple chemical structure, amino hormones are incredibly diverse and play crucial roles in regulating a wide range of physiological processes. They are synthesized in endocrine glands or specialized cells and are released into the bloodstream to travel to target cells. These target cells possess specific receptors that bind to the amino hormone, initiating a signaling cascade that ultimately alters cellular function.

The small size and lipophobic nature of most amino hormones mean they typically cannot cross the cell membrane. Instead, they bind to cell surface receptors, activating second messenger systems within the cell. This mechanism allows for rapid and significant physiological responses. Examples of amino hormones include thyroid hormones, which are derived from tyrosine and regulate metabolism, and catecholamines like epinephrine and norepinephrine, also derived from tyrosine, which are involved in the "fight-or-flight" response. Melatonin, derived from tryptophan, regulates sleep-wake cycles. The specific amino acid precursor influences the structure and function of the resulting amino hormone. Despite originating from a single amino acid, post-translational modifications can further diversify their actions.