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Unformatted text preview: 3) Hormones produced in small amounts -- often secreted in bursts (pulsatile) secreted 4) • 4) Hormones affect metabolic processes in most cells (buildup & breakdown of carbohydrates, lipids, & proteins) lipids, 5) • 5) Hormones affect only those cells that have receptors for the hormone receptors Chemical Structures of Hormones
Protein • Protein hormones (strings of amino acids) acids) e.g., vasopressin
(a)ÑProtein hormone H 2N Different amino acids Amine • Amine hormones (single amino acids) (single e.g., thyroid hormone COOH Steroid • Steroid hormones e.g., testosterone, (four carbon rings) (four
estrogen Adrenocorticotropic hormone (ACTH) (b)ÑSteroid hormone OH CH 3 HO I Estradiol (c)ÑAmine hormone I O I CH 2 CHCOOH NH 2 HO I Thyroxine Effects of Hormones on Cells
Promote • Promote the proliferation, growth, and differentiation of cells, for example: differentiation growth hormone promotes cell growth steroid hormones cause secondary sex characteristics • Modulate cellular activity hormones affect metabolic rate in all cells hormones can affect excitability of neurons hormones can affect hormone production in other endocrine cells Two Cellular Mechanisms of Action
Protein • Protein and amine hormones bind to metabotropic receptors on the cell surface the Activate G-protein Activate mediated second messenger cascades messenger Protein and amine Protein hormones are considered fast acting (seconds to minutes) but this is still very slow compared to neurotransmitters like glutamate (milliseconds) glutamate • • Two Cellular Mechanisms of Action
Steroid • Steroid hormones pass • • • • through cell membranes through Bind receptors located Bind inside the cell inside The steroid hormone and The receptor form a complex which then binds to DNA which Then acts as a transcription Then factor (alters gene expression) expression) Steroid hormones acting Steroid inside th...
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This note was uploaded on 02/18/2011 for the course PSYCH 230 taught by Professor Unkown during the Winter '08 term at University of Michigan.
- Winter '08