Cell Signaling Study Guide Questions Flashcards
What is the signal transduction pathway?
The series of steps involved in the conversation of a signal on a cell’s surface to a cellular response
What are the 3 stages of cell signaling?
Reception- Signal molecule is received
Transduction- the transfer of information
Response- Cellular Response to the Signal
State where the signal receptors may be located in target cells.
Plasma Membrane Proteins
What is a G-Protein linked receptor?
A GTP-binding protein that relays signals from a plasma membrane signal receptor, to other signal transduction proteins inside the cell.
What is a tyrosine-kinase receptor?
Receptor proteins with enzymatic activity that can trigger several pathway at once.
What is a ligand-gated ion channel?
A protein pore in cellular membranes that opens or closes in response to a signaling chemical, allowing or blocking the flow of specific ions.
What are 2 advantages of using a multi step pathway in the transduction stage of cell signaling?
- allows a small number of extracellular signaling molecules to be amplified to produce a large cellular response
- provide opportunity for regulation and coordination.
Explain how original signal molecule can produce a cellular response when it may not even enter the target cell.
The signal molecule binds a receptor on the surface of the cell. This receptor is embedded in the cell membrane. Upon binding of a signal molecule the receptor will become active
Define the term ‘second messenger’
Second messengers participate in pathways initiated by both G protein-coupled receptors and receptor tyrosine kinases.
How is cAMP formed?
A second messenger; synthesized from ATP by the action of the enzyme adenylyl cyclase.
Describe how the cytosolic concentration of Ca 2+ is involved in signal transduction.
Used as a secondary messenger
How is signal amplification accomplished in target cells?
Signal moves through protein kinase 1, protein kinase 2, and so on until it triggers the cellular response
Explain why different types of cells may respond differently to the same signal molecule
each type of cell has its own complement of proteins
What is a Scaffolding Protein?
A type of large relay protein to which several other relay proteins are simultaneously attached to increase the efficiency of signal transduction.
