Section 6 Flashcards
Endocrine system makes chemical signals ….
to help body grow and maintain homeostasis
These chemicals control what type of processes?
cell division, cell death, sexual development or affecting body temperature, alertness, or salt levels
what are these chemical signals called? (named by endocrine system)
hormones
what are hormones made in
organs called glands
glands release hormones in the blood stream and they come in contact with many cells, when will it interact?
cell with specific receptors
what will happen if a hormone reaches a cell with no specific receptor
nothing
what will happen if a hormone reaches a cell with the correct receptor
it binds to the cell and prompts the cell to make or activate certain proteins or enzymes
what is a target cell?
cells that have
receptors for a specific
hormone
what are steroid hormones made of?
of cholesterol, a type of lipid
what are nonsteroid hormones made of?
one or more amino acids
how can steroid hormones enter its target cell?
by diffusing in its membrane
Once inside, the steroid hormone attaches to a receptor protein, which transports the protein into the nucleus. What happens when its inside?
the steroid hormone binds to the cell’s DNA. This binding causes the cell to produce the proteins that are coded by that portion of DNA.
nonsteroid hormones dont enter the cell why?
It is not fat soluble, so it cannot diffuse across the plasma membrane of a target cell
Nonsteroid hormones do not enter their target cells. These hormones bind to protein receptors on a cell’s membrane and cause chemical reactions to take place inside the cell.
what do the chemical receptors activate (nonsteriod).
activates molecules inside the cell. These molecules, called second messengers
what do second messengers do?
react with still other molecules inside the cell. The products of these reactions might initiate other chemical reactions in the cell or activate a gene in the nucleus.
