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How does protein hormones reach their target cells?
Usually in blood plasma, which carries them to their target cells. They 'recognize' these cells based on receptors on the cell membranes to which they bind.
Are hormones target molecules or signal molecules?
Hormones affect target cells because target cells have receptors that bind with certain hormones (they're specific). If a cell does not have a receptor then it is not affected by hormones. Target cells (which do have the receptor for a particular hormone) would be affected by the hormone.
Why must some hormones bind to membrane receptor on a target cell's surface in order to activate it?
because they cannot cross cell membranes
explain why hormones in the bloodstream are able only to affect target cells/organs and not other cells/organs?
Hormones in the bloodstream are able to affect target cells/organs and not other cells/organs because of selective permeability. This means that hormones are only able to pass through the cell membrane of certain cells and organs, and not through the cell membrane of other cells and organs. The cell membrane of the target cells and organs are specialized to allow the hormones to pass through, while the cell membrane of other cells and organs are not specialized and are therefore impermeable to the hormones. This is due to the presence of receptor proteins on the cell membrane of the target cells and organs. These receptor proteins can bind to the hormones and facilitate their entry into the cell. Since these receptor proteins are not present on the cell membrane of other cells and organs, the hormones are unable to bind to them and therefore unable to cross the cell membrane. In addition, hormones can be broken down by enzymes in the bloodstream, which means they can’t reach their target cells and organs if they are exposed to the enzymes. This further ensures that hormones only affect the target cells and organs, and not other cells and organs. In summary, hormones in the bloodstream are able to affect target cells and organs and not other cells and organs because of selective permeability and the presence of receptor proteins on the cell membrane of the target cells and organs. Other cells and organs do not have these specialized receptor proteins and therefore cannot be affected by the hormones.
Which hormone affect only certain cells?
Because they only activate target cells that have special receptors that only work when that specific hormone attaches to it.
What are the structures that allow hormones to bind to their target cells?
Receptors allow hormones to bind to their target cells.
How does protein hormones reach their target cells?
Usually in blood plasma, which carries them to their target cells. They 'recognize' these cells based on receptors on the cell membranes to which they bind.
A steroid hormone acts on a target cell by?
When receptors bind at the surface of a membrane, second messengers are released. This is how peptide hormones and catecholamines affect target organ cells.
Are hormones target molecules or signal molecules?
Hormones affect target cells because target cells have receptors that bind with certain hormones (they're specific). If a cell does not have a receptor then it is not affected by hormones. Target cells (which do have the receptor for a particular hormone) would be affected by the hormone.
Why must some hormones bind to membrane receptor on a target cell's surface in order to activate it?
because they cannot cross cell membranes
explain why hormones in the bloodstream are able only to affect target cells/organs and not other cells/organs?
Hormones in the bloodstream are able to affect target cells/organs and not other cells/organs because of selective permeability. This means that hormones are only able to pass through the cell membrane of certain cells and organs, and not through the cell membrane of other cells and organs. The cell membrane of the target cells and organs are specialized to allow the hormones to pass through, while the cell membrane of other cells and organs are not specialized and are therefore impermeable to the hormones. This is due to the presence of receptor proteins on the cell membrane of the target cells and organs. These receptor proteins can bind to the hormones and facilitate their entry into the cell. Since these receptor proteins are not present on the cell membrane of other cells and organs, the hormones are unable to bind to them and therefore unable to cross the cell membrane. In addition, hormones can be broken down by enzymes in the bloodstream, which means they can’t reach their target cells and organs if they are exposed to the enzymes. This further ensures that hormones only affect the target cells and organs, and not other cells and organs. In summary, hormones in the bloodstream are able to affect target cells and organs and not other cells and organs because of selective permeability and the presence of receptor proteins on the cell membrane of the target cells and organs. Other cells and organs do not have these specialized receptor proteins and therefore cannot be affected by the hormones.
Which hormone affect only certain cells?
Because they only activate target cells that have special receptors that only work when that specific hormone attaches to it.
How do non steroid hormones control their target cells?
They: Bind to cell membrane receptors Use cAMP as a second messenger and they cause a cascade amplification reaction
How do the signals of the endocrine system get transmitted to their appropriate target cells?
The endocrine system is a system of glands that secrete hormones (made of proteins) into the blood stream. Once in the blood, these hormones bind to other protein called receptors in the membranes of the target cells. This is how signals are transmitted
Do hormones bind receptors at the target cells?
Lock and Key to the Nth Degree. When any one of 'very many' intercellular 'blood borne' Activating Factors finds & fits-to a Cell Surface Receptor, this causes conformational changes to the 'Transmembrane Signal Proteins' that rapidly become apparent on the cytoplasmic 'side' of the cell membrane as another signal or set of signals, usually directed to the Nucleus.
What hormones can enter the target cell and bind to receptors in the nucleus?
steriod hormones - since they are lipophilic and fusses with the membrane to enter teh cell.
Why target cell respond to the hormone while others are uneffected?
Target cells respond to hormones because they have specific receptors for the hormone on their cell membrane or inside the cell. These receptors enable the hormone to bind and initiate a cellular response. Other cells that do not have the specific receptors for that hormone are unaffected because they cannot bind to the hormone or activate the necessary signaling pathways.
