Notes
Peptide and Protein Hormones
Sections
Peptide and Protein Hormone Physiology
Synthesis:
- Synthesized and then stored in secretory vesicles.
- First, within the nucleus of a cell, the gene for a hormone is transcribed as mRNA
- The mRNA moves to the ribosomes, where it is translated to create a preprohormone;
- The preprohormone moves to the endoplasmic reticulum, where it is converted to a prohormone;
- Finally, the prohormone is transported to the golgi apparatus to be packaged into secretory vesicles; within these vesicles, peptide cleavage produces the final hormone product.
- The hormone is stored until its release is triggered.
Transport:
- Travels freely in the blood; recall that this is because it is water soluble, and readily dissolves.
Mechanisms of Action:
- Peptide hormone binds cell membrane surface receptor and the hormone-receptor complex activates second messenger systems to initiate protein modification and synthesis.