Chemistry of Hormones - Summary & Explanation

**[Chemistry of Hormones]** **[Defination:]** A hormone is a chemical transmitter. It is released in small amounts from glands, and is transported in the bloodstream to target organs or other cells. Hormones are *[chemical messengers]*, transferring information and instructions from one set of cel...

**[Chemistry of Hormones]** **[Defination:]** A hormone is a chemical transmitter. It is released in small amounts from glands, and is transported in the bloodstream to target organs or other cells. Hormones are *[chemical messengers]*, transferring information and instructions from one set of cells to another. -Hormones regulate growth, development, mood, tissue function, metabolism, and sexual function. -[Hypo secretion or Hypersecretion] of any hormone can be harmful to the body. \- Controlling the production of hormones can treat many hormonal disorders in the body. [Classifications of hormones according to chemical nature into:] **[Two main groups]:** 1. [Amino acid--based]: - Proteins - Peptides (chains of amino acids; smaller than proteins) - Amines (a derivative of ammonia) 2. [Steroids]---made from cholesterol (lipid based) [Local Hormones]: 3. [Prostaglandins]--- made from highly active lipids that are released from almost all cell membranes. **[Hormone specificity]** [ 1-Hormones are specific] \- Target a cell or organ \- Target cells must have specific protein receptors 2-Hormone binding [alters cellular activity] 3-The act of a hormone binding to its target cell is very similar to that of an enzyme and its substrate- like a lock and key mechanism. **[Steroid Hormone Action]** 1. Diffuse directly through cell membrane 2. Enter the nucleus 3. Bind to a receptor protein [within the nucleus] 4. This *[hormone-receptor complex]* binds to specific sites on the cell's DNA 5. Certain genes are activated to synthesize new proteins **Steroid Hormones Action** **[Second-Messenger System (non-steroids)]** 1. Hormone (first messenger) binds to a *membrane receptor* 2. Activated receptor sets off a series of reactions that activates an enzyme 3. Enzyme catalyzes a reaction to produce a second messenger 4. Second messenger manage additional intracellular changes to promote a specific response in the target cell  **Non-steroid Hormones Action** http://www.cancernetwork.com/image/image\_gallery?img\_id=1170540&t=1217445044035