Signaling Pathway in Hormones - -There are three classes of...

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AP Biology Signaling Pathway in Hormones 1) Intercellular Communication by Secreted Molecules Local Signaling = Secreted molecules that act over short distances and reach their target cells solely by diffusion a) Endocrine Signaling = Secreted molecules diffuse into the bloodstream and trigger responses in target cells anywhere in the body b) Paracrine Signaling = Secreted molecules diffuse locally and trigger a response in neighboring cells c) Autocrine Signaling = Secreted molecules diffuse locally and trigger a response in the cells and secrete them d) Synaptic Signaling = Neurotransmitters diffuse across synapses and trigger response in cells of target tissues e) Neuroendocrine Signaling = Neurohormones diffuse into the bloodstream and trigger responses in target cells anywhere in the body 2) Cellular Response Pathways - Receptor location determines the duration of the cellular signaling and how quickly the cell signaling is propagated
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Unformatted text preview: -There are three classes of hormones: amines & peptides (derived from amino acids) and steroids (derived from cholesterol) a) Water-soluble Hormones (Amines & Peptides) Hydrophilic receptor(cell-surface receptors); can’t penetrate cell membrane Work through signal transduction pathway; transmit signal to 2 nd messenger inside cell, which triggers a response Example) epinephrine binds to liver cells and causes cascade that leads to conversion of glycogen into glucose b) Water-insoluble Hormones (Steroids) Hormones bind to lipid soluble receptors (intracellular receptors) in the cell Remember, they are intracellular receptors, not intercellular receptors Act as transcription factors, which means that it changes the expression of gene in the nucleus Example) Testosterone and estrogen enter nuclei of target cells, bind to DNA, and stimulate transcription of certain genes...
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This note was uploaded on 02/11/2012 for the course ZOOLOGY 152 taught by Professor Stephengammie during the Fall '11 term at University of Wisconsin Colleges Online.

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