Download Types of Hormones

Types of Hormones
Steroid Hormones
1. As lipids, the steroid hormones
can cross directly through the
cell membrane and
2. Bind to receptor proteins in
the cytoplasm or inside the
nucleus of the target cells;
3. Together, they form a
“hormone-receptor complex”
4. which serves as a transcription
factor, promoting or inhibiting
5. transcription and
6. translation of genes.
Example Steroid Hormones
These are the three
we’ll learn about
estrogen
Protein Hormones
1.
2.
3.
Are hydrophilic, so they cannot pass
through the hydrophobic middle of the
cell membrane.
Bind to receptor proteins on the cell
membrane surface.
The binding of the hormone triggers a
cascade of chemical reactions
mediated by chemicals called second
messengers, which are small
molecules that can quickly spread
throughout the cytoplasm and send
signals throughout the cell. The two
most common second messengers are
calcium ions and a molecule called
cyclic AMP (cAMP)
4. The second messengers effect the
cells functioning by activating or
inactivating enzymes.
Example Protein Hormones
D.5.U2 Steroid hormones bind to receptor proteins in the cytoplasm of the target cell to form a receptor–
hormone complex.
 Describe the mechanism of steroid hormone action.
 List two example steroid hormones.
D.5.U3 The receptor–hormone complex promotes the transcription of specific genes.
 List locations at which a steroid hormone binds its receptor.
 Review the function of a “transcription factor”
D.5.U4 Peptide hormones bind to receptors in the plasma membrane of the target cell.
 State the location at which a protein hormone binds its receptor.
 List two example protein hormones.
D.5.U5 Binding of hormones to membrane receptors activates a cascade mediated by a second messenger
inside the cell.
 List the two most common second messengers.
 Define “second messenger system.”