[12] Signal Transduction Pathways Flashcards
What is a signal transduction pathway?
A series of steps by which a signal on a cell’s surface is converted into a specific cellular response.
What initiates a signal transduction pathway?
The binding of a signaling molecule to a receptor on the cell surface.
What are the major components of a signal transduction pathway?
- Extracellular signaling molecule
- Receptor
- Intracellular signaling molecules
- Effector proteins
What is a receptor in signal transduction?
A protein that binds signaling molecules and initiates a physiological response.
What is an effector protein in a signal transduction pathway?
It carries out the final response in the pathway.
What is a G protein-coupled receptor?
A cell surface receptor that works with the help of a G protein.
What is a ligand-gated ion channel?
A type of receptor that can open or close an ion channel when a signaling molecule binds.
What role does a second messenger play in signal transduction pathways?
It relays the signal from the receptor to downstream signaling molecules.
Give an example of a second messenger.
- cAMP
- IP3
- Ca2+.
What is phosphorylation in signal transduction pathways?
The addition of a phosphate group to a protein or other organic molecule.
What enzyme is responsible for phosphorylation?
Protein kinase.
What enzyme is responsible for removing a phosphate group in signal transduction pathways?
Protein phosphatase.
What is a phosphorylation cascade?
A sequence of events where one enzyme phosphorylates another, causing a chain reaction.
What is meant by signal amplification in signal transduction pathways?
The process by which a single signal molecule can trigger a large response.
How do intracellular receptors work in signal transduction pathways?
They bind to signaling molecules that can cross the plasma membrane, leading to a cellular response.
