Chapter nine: Cellular Signaling
9.1
Yeast cells secrete specific enzymes that only bind to receptor of another yeast cell. The cells
have specific receptors for those enzymes that are secreted from the other yeast cell.
Signal transduction pathway is a series of steps linking a mechanical, chemical or electrical
stimulus to a specific cellular response.
Prokaryotes secrete certain molecules that can be detected by other bacteria (believed it has
evolved to eukaryotes cell signals). Bacteria sense the concentration of the secreted
molecules is called: quorum sensing, this way different bacteria can work together.
Local signaling:
Both animal and plant cells have gap junctions
with connected cytosol in which dissolved
molecules can move freely to the neighbor cell.
Cells also can have molecules on their surface.
Certain molecules can fit perfectly together. As
they are connected a response is triggered in
(sometimes both) cells.
Paracrine signaling: certain molecules are
secreted (by secretory vesicles) from the cell.
These molecules travel only short distances and
trigger responses from target cells. The secreted
molecules are called local regulators. Paracrine
signaling usually occurs in embryonic
development and the immune response. In
animals, growth factors, are compounds that
stimulate surrounding cells to grow and divide.
Synaptic signaling is a more specialized type of local signaling. This occurs in the animal nerve
system. An electrical signal was sent along the nerve cell and triggers the release of
neurotransmitter molecules. These molecules act as chemical signals diffusing across the
synapse. The target cell is very close to the synapse and triggered by those secreted
molecules.
Long-distance signaling:
Plants and animals use hormones for long-distance signaling.
Hormone signaling is also known as endocrine signaling,
specialized hormones travel along the circulatory system to
other parts of the body.
Plant growth factors (plant hormones) travel through vessels
but more often are released into the air and reach other cells.
Hormones vary widely in shape and type. Some are small
enough to fit through cell walls, other are very large (insulin).
The information conveyed by a signaling molecules that’s
bound to the right receptor must be transduced (put into
another form) inside the cell before it can respond. This
usually only happens in animal cells.
9.1
Yeast cells secrete specific enzymes that only bind to receptor of another yeast cell. The cells
have specific receptors for those enzymes that are secreted from the other yeast cell.
Signal transduction pathway is a series of steps linking a mechanical, chemical or electrical
stimulus to a specific cellular response.
Prokaryotes secrete certain molecules that can be detected by other bacteria (believed it has
evolved to eukaryotes cell signals). Bacteria sense the concentration of the secreted
molecules is called: quorum sensing, this way different bacteria can work together.
Local signaling:
Both animal and plant cells have gap junctions
with connected cytosol in which dissolved
molecules can move freely to the neighbor cell.
Cells also can have molecules on their surface.
Certain molecules can fit perfectly together. As
they are connected a response is triggered in
(sometimes both) cells.
Paracrine signaling: certain molecules are
secreted (by secretory vesicles) from the cell.
These molecules travel only short distances and
trigger responses from target cells. The secreted
molecules are called local regulators. Paracrine
signaling usually occurs in embryonic
development and the immune response. In
animals, growth factors, are compounds that
stimulate surrounding cells to grow and divide.
Synaptic signaling is a more specialized type of local signaling. This occurs in the animal nerve
system. An electrical signal was sent along the nerve cell and triggers the release of
neurotransmitter molecules. These molecules act as chemical signals diffusing across the
synapse. The target cell is very close to the synapse and triggered by those secreted
molecules.
Long-distance signaling:
Plants and animals use hormones for long-distance signaling.
Hormone signaling is also known as endocrine signaling,
specialized hormones travel along the circulatory system to
other parts of the body.
Plant growth factors (plant hormones) travel through vessels
but more often are released into the air and reach other cells.
Hormones vary widely in shape and type. Some are small
enough to fit through cell walls, other are very large (insulin).
The information conveyed by a signaling molecules that’s
bound to the right receptor must be transduced (put into
another form) inside the cell before it can respond. This
usually only happens in animal cells.
