HBG 16 ( Hormones and Signal Transduction)

• Types of hormones:

  • Protein hormones (or polypeptide hormones) made of chains of amino acids. Example: ADH (antidiuretic hormone) decreases blood pressure
  • Steroid hormones derived from lipids. Example: Reproductive hormones like testosterone and estrogen
  • Amine hormones derived from amino acids. Example: Epinephrine helps regulate the fight-or-flight response
• The structure of hormones dictates various physiological actions, from fear to hunger to urination to growth and childbirth
• Regulation of transcription by hormones that act on the receptor inside the cell
• Secondary messengers:

  • Intracellular signaling molecules released by the cell to trigger physiological changes
  • Amplify components of intracellular signal transduction cascades
  • Examples: cyclic AMP, cyclic GMP, inositol trisphosphate, diacylglycerol, and calcium
• Types of Second Messengers:

  1. Hydrophobic molecules: membrane-associated e.g. diacylglycerol, phosphatidylinositol
  2. Hydrophilic molecules: water-soluble molecules, such as cAMP, cGMP, IP3, and Ca2+, located within the cytosol
  3. Gases: nitric oxide (NO), carbon monoxide (CO), and hydrogen sulfide (H2S) can diffuse both through cytosol and across cellular membranes
• Types of hormones:

  • Protein hormones (or polypeptide hormones) are made of chains of amino acids. Example: ADH (antidiuretic hormone) decreases blood pressure.
  • Steroid hormones are derived from lipids. Example: Reproductive hormones like testosterone and estrogen.
  • Amine hormones are derived from amino acids. Example: Epinephrine helps regulate the fight-or-flight response
• The structure of hormones dictates various physiological actions, from fear to hunger to urination to growth and childbirth
• Regulation of transcription by hormones that act on the receptor inside the cell
• Secondary messengers are intracellular signaling molecules released by the cell to trigger physiological changes and amplify components of intracellular signal transduction cascades
• Examples of secondary messengers:

  • Cyclic AMP
  • Cyclic GMP
  • Inositol trisphosphate
  • Diacylglycerol
  • Calcium
• Types of Second Messengers:

  1. Hydrophobic molecules: membrane-associated, e.g., diacylglycerol, phosphatidylinositol
  2. Hydrophilic molecules: water-soluble molecules, such as cAMP, cGMP, IP3, and Ca2+, located within the cytosol
  3. Gases: nitric oxide (NO), carbon monoxide (CO), and hydrogen sulfide (H2S) can diffuse both through cytosol and across cellular membranes