Hormones - 2

Hormones

Chemical messages carried by the blood that allow one part of the body to give instructions to another part

• The endocrine system is a system of hormone secreting glands, lcoated in various parts of te body

• Hormones bind to receptors (proteins) of cells

  • Inside or outside of cell

  • Specific receptors for specific hormones

Steroid Hormones Pathway

Composed of lipids

1. Hormones passes through plasma membrane (lipid-soluble)

2. Hormone bidns to receptor inside cells

   1. Sometimes in nucleus

3. Hormone receptor complex binds to the control sequences of a specific gene, turning it on or off

   1. Complex is a transcription factor

Essentially process of inhibiting or activating the transcription of a specific gene

Water-Soluble Hormones

Composed of amino acids

1. Hormone binds to a receptor protein (receptor conformational change

2. Receptor protein activates a signal transduction pathway

3. Series of relay molecules transmits the signal to a protein that carries out the cell’s response

• Second messengers are molecules that relay signals from receptors on the cell surface to target molecules in the cytoplasm

  • Hormone impact is greatly amplified

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