PEPTIDE HORMONE Meaning and
Definition
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A peptide hormone refers to a specific type of hormone that acts as a signaling molecule within the body. It is composed of amino acids and generally exists as a relatively short chain of these amino acids, typically containing 3 to 100 amino acids. Peptide hormones are produced by various organs and tissues throughout the body, most notably by the endocrine glands. They are released into the bloodstream, where they travel to specific target cells or organs to exert their effects.
Peptide hormones play a crucial role in regulating various biological processes and maintaining homeostasis. They function by binding to specific receptors on the surface of target cells, initiating a cascade of biochemical events. These hormones are involved in diverse physiological functions, including metabolism, growth and development, reproduction, and immune response.
Notable examples of peptide hormones include insulin, glucagon, growth hormone, oxytocin, and prolactin. Each of these hormones has unique effects on the body and is responsible for various biological activities. For instance, insulin regulates blood sugar levels by promoting the uptake of glucose by cells, while growth hormone stimulates cell growth and repair.
Furthermore, peptide hormones are often regulated by a negative feedback mechanism, where elevated hormone levels suppress further hormone release. This ensures that the body maintains an optimal balance of hormones and prevents excessive hormone production.
Etymology of PEPTIDE HORMONE
The word "peptide hormone" has its etymology rooted in the combination of two components: "peptide" and "hormone".
1. Peptide: The term "peptide" originates from the Greek word "peptos", meaning "digested" or "broken down". It was first coined by the German physiologist Emil Fischer in 1901 to describe naturally occurring compounds derived from the digestion of proteins. Peptides are short chains of amino acids connected by peptide bonds.
2. Hormone: The word "hormone" derives from the Greek term "hormon", meaning "that which sets in motion". It was introduced by the English physiologist Ernest Starling in 1905. Hormones are chemical messengers produced by various glands in the body. They are secreted into the bloodstream and play a vital role in regulating bodily functions and maintaining homeostasis.
