steroid & amine/protein hormones

• Steroid Hormones bind to what in blood stream?

  transport protein
• Protein hormones bind to what in bloodstream?

  nothing
• What soluble is steroid hormone and what effect does this have?

  Lipid soluble; easily diffuses through lipid soluble part of phospholipid bilayers & enters cytosol
• What soluble is protein hormone and what effect does this have?

  Water-soluble; unable to enter target cells.

  ·        Instead, binds with receptors on target cells cell membrane
• Where does steroid hormone bind to?

  specific sites on cell DNA; forming hormone-receptor complex
• Where does protein hormone bind to?

  receptors on target cells cell membrane, forming hormone receptor complex
• What is the effect of hormone receptor complex with protein hormones?

  Sets off series of reactions that activates an enzyme.

  • Enzyme catalyzes reaction, producing 2nd messenger molecule, thus changing cell metabolism.
• whats the effect of hormone receptor complex with steroid hormone?

  Causes change in gene transcription & translation:

  • Activates certain genes to transcribe mRNA
  • mRNA is translated in cytoplasm
  • Synthesis of new proteins