Cell Signaling 2.4 U2 Flashcards
What do cells need to be able to do?
Get information from their surroundings and other cellsSend information out for other cells to receiveIn multicellular organisms, be able to coordinate complex functions that involve many different cellsCommunicate within themselves! (ex. organelle to organelle)
What is a ligand?
Signaling molecule that binds to a certain receptor
What is a receptor?
A protein that “receives” the ligand and causes some effect
What is a target cell?
A cell that has the receptor for a particular ligand
What is a non-target cell?
A cell that does NOT have the receptor for a particular ligand
What are the types of receptors?
Internal receptorsCell-surface receptors
What are internal receptors?
In cytoplasmLigand has to enter cell to bind
What are cell-surface receptors?
In cell membraneThree main types:Ion-channel linked receptorsG-protein coupled receptorsEnzyme-linked receptors
What is a ion-channel linked?
When the ligand binds, the transmembrane channel opens, allowing ions to move through it.
What is a G-protein coupled?
When the ligand binds, the receptor interacts with a G-protein which starts the signal transduction chain of events.The receptor has seven transmembrane regions.GTP to GDP
What is an enzyme-linked?
When the ligand binds, the receptor activates an enzyme, which starts the signal transduction chain of events.
What is a signal transduction?
IntracellularSeries of signaling events, like a chain reaction
What are the responses to cell signaling?
Depends on the particular signal! But, often:Changes in gene regulationTurning expression of certain genes on/offRegulates another protein’s activity
What are examples of responses to cell signaling?
A growth factor binding to a cell causes an increase in the expression of genes that allow the cell to grow and divide!When adrenaline binds to a muscle cell, it inactive the enzyme responsible for storing glucose and activates the enzyme responsible for producing glucose!
What is bacterial communication?
At a certain density, the cells “decide” to change what they are doing. This works by the bacteria cell producing a ligand. When there is a low density of cells, there are less receptors for the ligand to bind to which results in no cellular response. When there is a higher concentration, there are more ligands and receptors. Once the ligands bind, they activate specific genes in the chromosomes of bacterial cells.
