Cell Communication Flashcards
How do cells monitor and communicate with their environment?
Through receptors
Ex: Glucose signaling yeast. Due to glucose in the environment, the yeast cell underwent a cellular response by synthesizing more glucose transporters and enzymes that are needed to metabolize the glucose.
Why is cellular response critical to the survival of cells?
helps avoid overgrowth , lack of control would lead to tumors (cancer)
what are the 5 ways cells communicate with each other to coordinate their responses to signals from the environment or each other?
- Direct intercellular signaling
- Contact Dependent Signaling
- Autocrine signaling
- Paracrine signaling
- Endocrine signaling
What is Direct intercellular signaling?
Cell junctions allow signaling molecules to pass directly from one cell to another
Ex: Gap junctions connecting cardiac muscle cells.
What is Contact-dependent signaling?
Membrane-bound signals bind to receptors on nearby cells
Important during development for proper location
What is Autocrine signaling?
Cells secrete signaling molecules that bind to their own cell surface pr similar neighboring cells.
What is Paracrine signaling?
Signal does not affect originating cell, but does influence nearby cells.
What is Endocrine signaling?
Hormones secreted from endocrine organs are carried through the blood over long distances to affect target cells.
Responses can be intermediate or long term.
What are the three stages of cell Signaling?
Activation, transduction, response
- Receptor Activation
(Signaling molecules binds to receptor) - Signal transduction
(Activated receptor stimulates a series of proteins that form a signal transduction pathway.) - Cellular response
(The signal transduction pathway affects the functions and/or amounts of cellular proteins, thereby producing a cellular response.)
What are some examples of cellular response?
Change in enzyme activity
Change in function of structural proteins
Change in gene expression
What are the 3 cell surface receptors?
Enzyme-Linked Receptors
Gene-Protein Coupled Receptors
Ligand-Gated Ion Channels
What is a ligand?
A signaling molecule
Enzyme linked receptors
What is Extracellular domain?
A signaling molecule (substrate) binds and activates the catalytic domain of the receptor
Enzyme linked receptors
What is intracellular domain?
Becomes a functional catalyst that promotes a reaction
What is the process with a G-protein coupled receptor?
- A signaling molecule binds to a GPCR (receptor) causing it to bind to a G protein
- The G protein releases its GDP protein and binds to GTP protein instead.
Then it separates from the receptor into an alpha subunit and a Beta dimer. These subunits promote a cellular response. - The signaling molecule dissociates from the receptor and the alpha subunit hydrolyses GTP back into GDP + P, the alpha subunit and the beta dime reassociate.
