How do hormones differ from enzymes and neurotransmitters?
Hormone are chemicals produced by the cells of endocrine glands, travel through a medium, such as the bloodstream in mammals, and have an effect at target cells by binding to receptors of these target cells.
For example, insulin is produced by the pancreatic cells and allows the absorption of glucose, blood sugar, by cells throughout the body.
Neurotransmitters, are chemicals produced by neurons that send a message from neuron to neuron or from neuron to muscle.
Acetylcholine is a neurotransmitter that is released by a neuron to another neuron or to a muscle.
Enzymes are chemical catalysts that speed up chemical reactions.
Acetylcholine esterase is an enzyme that degrades acetylcholine.
Enzymes and Neurotransmitters are made of the building blocks of proteins, which are amino acids and polypeptides.
Hormones are made of polypeptides, lipids, or cholesterol based compounds.