PSL201Y1 Final: Hormones General overview of hormones (peptide, steroid, and amide). Includes information on each type, examples and more general hormone information.
Document Summary
Hormones are classified into three subsets: peptide, steroid and amine. Peptide hormones are made of 3 amino acids or more, and make up most hormones. They are made in advance and stored in vesicles to await a stimulus to signal that they are needed. They are not bonded to carriers and therefore have a short half life, and are water soluble. They are too large to pass into a cell, therefore their receptors are on the cell"s plasma membrane: for example, insulin is first preproinsulin and modified to proinsulin in the er. After that it goes to the golgi apparatus where it is made into insulin, along with the nonactive peptide fragment c peptide. It"s stored in a vesicle and awaits a signal to undergo exocytosis and enter the blood. Steroid hormones are made only from cholesterol and are made on demand. They are water insoluble and so are bonded to carriers and have a long half life.
