Lecture 05

• What is the purpose of exploring receptors and signalling?

  To understand cell interaction with the environment
• What does the term 'receptor' refer to?

  A molecular structure that binds specific molecules
• What is a ligand?

  A molecule that binds specifically to a receptor
• What role do receptors play in cellular signalling?

  They transmit information from ligands to cells
• What are the types of cellular responses to ligands?

  Synthesis, secretion, adherence, chemotaxis, phagocytosis

  
• What are examples of extracellular signalling molecules?

  Growth factors, hormones, cytokines, neurotransmitters
• How do receptors initiate intracellular signalling cascades?

  By binding to cognate receptors on target cells
• What happens to a ligand after it binds to a receptor?

  It is modified or degraded by the cell
• What are the types of receptors mentioned?

  G-protein coupled, tyrosine kinases, ion-channels, toll-like receptors
• What is the structure of G-protein coupled receptors (GPCRs)?

  Made of alpha helix integral membrane proteins
• What role do GPCRs play in signal transduction?

  They transmit signals from extracellular molecules into the cell
• What occurs when GPCRs bind to a specific ligand?

  They activate intracellular signalling pathways
• What is the significance of GTP in GPCR signalling?

  It replaces GDP in G-proteins during activation
• What physiological processes are GPCRs involved in?

  Sensory perception, immune response, neurotransmission
• What is the role of adrenaline in the cell signalling pathway?

  It binds to adrenergic receptors activating G proteins

  
• What does adenylyl cyclase do in the signalling pathway?

  It converts ATP into cyclic AMP

  
• What is the effect of cyclic AMP in the cell?

  It stimulates further signalling cascades
• What is the function of receptor tyrosine kinases?

  They transfer phosphorus from ATP to proteins
• What happens when receptor tyrosine kinases are activated?

  They dimerise and phosphorylate each other

  
• What can hyperactivation of EGFR lead to?

  Dysregulation and tumorigenesis
• What is the role of acetylcholine in cell signalling?

  It sends signals from nerve cells to other cells
• How do ion channels function?

  They control the flow of ions across membranes
• What types of ion channels are there?

  Voltage-gated, ligand-gated, mechanically gated
• What can dysregulation of ion channels lead to?

  Diseases like epilepsy and cardiac arrhythmias
• What is the function of Toll-like receptors (TLRs)?

  They play a crucial role in the innate immune system
• What do TLRs recognise?

  Pathogen-associated molecular patterns (PAMPs)
• What is the outcome of TLR activation?

  Initiation of immune response signalling cascades
• What is cell signalling?

  The release of substances transmitting information
• What is the significance of ligand binding to receptors?

  It triggers a physiological effect in the cell

  
• What are the key components of cell responses to signalling?

  Synthesis, growth, interaction, and survival
• What is the role of receptor phosphorylation?

  It serves as docking sites for signalling proteins
• How do cells amplify signals during cell signalling?

  By triggering a chain of events after binding
• What are the steps in a typical cell signalling pathway?

  1. Signal initiated by chemical interaction
  2. Binding triggers a chain of events
  3. Signal is carried and amplified
  4. Cells send signalling molecules to others

  
• What are the definitions of key terms in cell signalling?

  • Cell signalling: Release of substances transmitting information
  • Ligand: Molecule that binds specifically to another molecule
  • Receptor: Structure that selectively binds a specific molecule