🧫 Cell Biology — Advanced#

Scope — Molecular regulation of signaling pathways, membrane biophysics, organelle biogenesis, and advanced cell cycle control.

Key concepts#

• Signal transduction — receptor types (GPCRs, RTKs), second messengers, phosphorylation cascades.
• Membrane biophysics — lipid rafts, curvature, membrane tension, and protein–lipid interactions.
• Organelle dynamics — mitochondrial fission/fusion, ER–mitochondria contact sites, autophagy mechanisms.

Seed Q&A triads#

• Q: How do receptor tyrosine kinases (RTKs) activate downstream signaling?
  A: Ligand binding induces dimerization and autophosphorylation, creating docking sites for adaptor proteins that propagate signaling cascades.

• Q: What is the role of mitophagy in cellular homeostasis?
  A: Selective autophagic removal of damaged mitochondria to prevent ROS accumulation and maintain metabolic health.

• Q: How does membrane curvature influence vesicle formation?
  A: Curvature-sensing and -inducing proteins (e.g., BAR domains, clathrin) stabilize curved membranes and drive budding.

Contributor prompts#

• Add a worked example tracing a GPCR → cAMP → PKA pathway and its cellular outcomes.
• Include a short note on experimental methods: live-cell imaging of organelle dynamics and common fluorescent markers.