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Chapter 11
Cell Communication
By: Jenna Alma, Robyn Alma,
Nicole Anichich, Sarika
Arora, AnaCristina Bedoya,
Renee Grasso, Victoria
Matiatos, and Danielle Sudol
Let’s Play Telephone!
Cell Signaling
• Cell-cell communication is the way cells “talk” to
each other
• Mating yeast cells: a cell and α cell
• a factor- signaling molecule that can bind to
specific receptor proteins
• a cells secrete this and send them to nearby α
cells
• at the same time α cells secrete an a factor and
send them to bind to a cells
• Transduced- the changing of a received signal
into a form usable to initiate a cellular response
• This form of cell signaling results in the fusion,
or mating, of the two cells where each cell has
genes from both original cells.
• Signal transduction pathway- a series of steps
that converts a received signal into a specific
cellular response
• Ex. Mating yeast cells
• -Occurs in animal cells as well
• Quorum sensing- the regulation of local density
by bacterial cells by the secretion of small
molecules that are detected by nearby bacterial
cells
• - Allows the cells to coordinate their production
efforts
• Biofilm- a collection of bacterial cells that adhere
to a surface to derive nutrients from it
• Ex. Teeth enamel
• -caused by quorum sensing
Local and Long Distance
Signaling
• Cells in multicellular organisms communicate
via chemical messengers
Types of Local Signals:
o Direct Contact
o Parascine Signaling
o Synaptic Signaling
Types of Long-Distance Signals:
o Endocrine Signaling
Local Signaling
• Direct Contact- the cytoplasms of adjacent cells
are connected by cell junctions
o Animal cells can communicate through cell-cell
recognition where membrane-bound cell-surface
molecules come in contact
• Local Regulators- influence cells in the vicinity
and are secreted by the signaling cell
o Growth factors- a class of local regulators
which consist of compounds that stimulate
nearby cells to grow and divide
• Paracine Signaling- occurs in animals where
many cells simultaneously receive and respond
to the molecules of growth factor produced in
their vicinity
• Synaptic Signaling- an electrical signal along a
nerve cell that triggers the secretion of
neurotransmitter molecules which then diffuse
across the synapse
o occurs in animal cells
Long-Distance Signaling
• Endocrine Signaling- special cells release
hormone molecules which travel by the
circulatory system to other parts of the body and
reach their target cells
o A.K.A. Hormone Signaling
o Hormones- chemicals that are used by animal
and plant cells in long distance-signaling
o Vary widely in size and shape
• The transmission of a signal through the nervous
system is an example of long-distance signaling
The Three Stages of Cell
Signaling
• E.W. Sutherland's work was the first thorough
study of cell signaling
• Breakdown of glycogen in our liver and skeletal
muscles is driven by the breakdown of the
animal hormone epinephrine
• Epinephrine functions:
•
Drives process of glycolysis
•
Stores fuel to be secreted when body is
mentally or physically stressed
• - Epinephrine doesn't just work by itself, it
requires:
• • Activation of a cytosolic enzyme
• • Interaction with other cells and the plasma
membrane
• WHY? CELL SIGNALING
•
•
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STAGE 1: Reception
A signal molecule binds to a receptor protein
Takes place in cell membrane or inside cell
Enacts "detection" of chemical signal
• STAGE 2: Transduction
• Binding to receptor changes it somehow, which
triggers a series of reactions down a series of
different molecules (the signal transduction
pathway)
• Relay molecules are spread out on pathway
• STAGE 3: Response
• Specific cellular activity is triggered by the
transduced signal
• Could drive processes such as activation of
specific genes, catalysis, or rearrangement of
cytoskeleton
Thank You!