All Flashcards
Define 'signal transduction pathway'.
A series of steps that amplify a small signal into a large cellular response.
What is a 'ligand' in cell signaling?
A signaling molecule that binds to a receptor protein.
Define 'receptor protein'.
A protein on a cell that binds to a ligand, initiating a cellular response.
What is 'phosphorylation'?
The process of adding a phosphate group to a protein, often activating it.
Define 'amplification' in signal transduction.
Making the cellular response bigger or faster, often through a cascade of activation steps.
What are 'secondary messengers'?
Molecules that relay signals from cell surface receptors to target molecules inside the cell, amplifying the signal.
What is the effect of a ligand binding to a receptor protein?
The receptor protein changes shape, initiating a signal transduction pathway.
What is the effect of phosphorylation of a protein?
The protein is often activated, leading to a cellular response.
What is the effect of activating adenylyl cyclase?
Adenylyl cyclase converts ATP to cAMP, a secondary messenger.
What is the effect of cAMP activation?
cAMP activates protein kinases, leading to further phosphorylation and a cellular response.
What is the effect of lipid hormones binding to intracellular receptors?
Production of transcription factors, leading to new protein synthesis and a longer-lasting cellular response.
What are the three main steps of cell communication?
- Reception 2. Transduction 3. Response
List the steps of G-protein-coupled receptor (GPCR) activation.
- Ligand binds to GPCR 2. GPCR changes shape, activating a G protein 3. G protein activates adenylyl cyclase 4. Adenylyl cyclase converts ATP to cAMP 5. cAMP activates other molecules, leading to a cellular response.
Describe the process of signal transduction.
A ligand binds to a receptor, triggering a cascade of intracellular events (phosphorylation, activation of secondary messengers) that amplify the signal and lead to a cellular response.