BIO 1140 Chapter Notes - Chapter 43: Salt Gland, Cell Membrane, Signal Transduction
Document Summary
Hormones control cell functions by binding to receptor molecules on or in their target cells. Small quantities of hormones can cause huge change because of amplification. A the secreted hormone may not be in an active form. Many hormones are secreted in an inactive form (a prohormone) and converted by target cells or enzymes in the blood/tissues into an active form . Prohormone: a precursor of a hormone; usually has minimal hormonal effect by itself. Peptide hormones are often synthesized as prohormones that undergo post-translational conversion to the active forms in the source cell. Sometimes further conversion after the hormone has been secreted (not as common) B hydrophilic hormones bind to surface receptors, activating protein kinases inside cells. Hormones that bind to receptors in the plasma membrane produce their responses through signal transduction pathways . When a surface receptor binds a hormone, it transmits a signal through the plasma membrane.