BIOD27H3 Chapter 7: Chapter 7 notes
Document Summary
Prohormones are chopped into active hormone and peptide fragments that are co- secreted. Peptide hormones dissolve in the plasma and have a short half life. They bind to surface receptors on their target cells and initiate rapid cellular responses through signal transduction. In some instances, peptide hormones also initiate synthesis of new proteins. Steroid hormones are synthesized as they are needed. They are hydrophobic and most steroid hormones in the blood are bound to protein carriers. Traditional steroid hormones are inside the target cell, where they turn genes on or off and direct the synthesis of new proteins. Cell response is slower than with peptide hormones. Steroid hormones may bind to membrane receptors and have nongenomic effects. Amine hormones may behave like a typical peptide hormones or like a combination of a steroid hormone and a peptide hormone. Control of hormone release classic endocrine cells act as both sensor and integrating center in the simple reflex pathway.
