Chemical Hormones Comparison

Created by

@DetachableHydra

Study Notes

Classification of Hormones

Hormones can be categorized into two main classes based on solubility: lipid-soluble and water-soluble.

Lipid-Soluble Hormones

Include steroid hormones, thyroid hormones (T3 and T4), and nitric oxide (NO).
Characteristics of steroid hormones: derived from cholesterol, exhibit a diverse range of functions due to unique chemical groups on their core structure.
T3 and T4 hormones: produced by attaching iodine to tyrosine, possess two benzene rings, enhancing their lipid solubility.
Nitric oxide (NO): operates as both a hormone and neurotransmitter, synthesized by nitric oxide synthase.

Water-Soluble Hormones

Comprise amine hormones, peptide and protein hormones, and eicosanoid hormones.
Amine hormones: synthesized from the decarboxylation of amino acids, retaining the amino group, with catecholamines (epinephrine, norepinephrine, dopamine) derived from tyrosine and histamine from histidine.
Peptide hormones: chains of 3 to 49 amino acids; examples include antidiuretic hormone and oxytocin. Protein hormones consist of 50 to 200 amino acids, such as human growth hormone and insulin.
Eicosanoid hormones: derived from arachidonic acid, include prostaglandins and leukotrienes, acting as local hormones and potentially as circulating hormones.

Hormone Transport in Blood

Water-soluble hormones circulate freely in the blood plasma without attachment to other molecules.
Lipid-soluble hormones are transported bound to proteins, synthesized by liver cells, enhancing their solubility in blood.

Functions of Transport Proteins

Temporarily increase water solubility of lipid-soluble hormones for better circulation.
Slow kidney filtration and hormone loss in urine.
Maintain a reserve of hormones readily available in the bloodstream.

Description

This quiz explores the two main classes of chemical hormones based on their solubility: lipid-soluble and water-soluble hormones. It provides insights into the characteristics and examples of each class, such as steroid hormones and thyroid hormones. Test your knowledge on the differentiation between these hormone types.