All Flashcards
Compare cell surface receptors and intracellular receptors.
Cell surface receptors: Located on the plasma membrane, bind to hydrophilic ligands. | Intracellular receptors: Located inside the cell, bind to hydrophobic ligands that can cross the membrane.
Differentiate between primary and secondary messengers.
Primary messenger: The initial signaling molecule (ligand) that binds to the receptor. | Secondary messenger: Small, non-protein molecules that relay and amplify the signal inside the cell.
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.
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.