1. Specific extracellular signal molecules require a cell surface receptor. What about the chemistry of these signals prevents them from diffusing across the cell membrane?
2. What is the difference between endocrine signaling, paracrine signaling and autocrine signaling?
3. Why do cellular signal molecules bing to a receptor using noncovalent forces rather than a covalent bond?
4. What is the different between kinases and phosphates? How do they impact activity of the target protein. Please give an example that involves kinases and phosphates.
5. How do kinases recognize their substrates and the proteins they act on?
6. What is the difference between the active form and inactive form of GTPase superfamily of proteins?
7. How are second messengers different from first messengers?