Key points and questions What are common components of a cellular signal transduction system? What principle types of intercellular communications are existing? What type (derivatives) of signaling molecules are known? What is a ligand? How can affinity be measured? What is an SH2 domain? How does a G-protein work? Which amino acids can be subjected to kinase reactions, what is the principle of a kinase reaction? How and where is the expression of a gene controlled? What are major features of transcription factors? What is a Northern Blot and how does it work? What is a reporter gene and what can be analyzed by their use? What is a nexus? What is the membrane potential, action potential and which ions contribute to it? How does a voltage gated ion channel work; what types of ligand gated channels can be ditinguished? How is a synapse composed? What is the action of Botox? What is acetylcholine, how is it synthesized and what types of acetylcholine receptors are known? What is serotonine? How is adrenaline synthesized and degraded? What is a MAO inhibitor and the result of its action? Describe the coupling of electric excitement and contraction at the skeletal muscle. What are typical features of a G-protein coupled receptor What are the effector enzymes and second messengers of Gs, Gi, Gp type of G-proteins? What is transducin? How is a receptor associated G-protein activated and what bacterial substances can interfere with that activation? How is diacylglycerol generated and what other products with second messenger function can thereby be generated? What is protein kinase C and how can it be activated? What is an EF-hand and for what is it characteristic? How can calcium activate glycogen breakdown? What is glucagon, how is it synthesized and what is its major second messenger? How can protein kinase A be activated? What do you understand under the term cAMP regulatory element binding protein (CREB) and how is this protein linked to the action of glucagon? What is major function of biotin in cells? Why does coffee increase the intracellular cAMP levels? What is rhodopsin and which are its major constituents? What are major differences between retinal rod and cone cells? How can light reduce the cGMP levels in rod and cone cells? What is the neurotransmitter released from rod and cone cells? What type of glutamate receptors can be distinguished on retinal bipolar cells? Why is beta-caroten important for the biochemistry of vision? Where is insulin produced, how is it stored and what is the major nutrient leading to its release? Describe insulin actions in liver, fat, and muscle. Give a schematic overview about the composition, organization, and functional features of the insulin receptor. What is the prerequisite for the recruitment of insulin receptor substrates to the insulin receptor? How can the insulin receptor lead to the activation of phosphatidylinositol 3-kinase? What is PTEN? What is protein kinase B (PKB) and which mechanisms lead to its full activation? How can protein kinase B activate glycogen synthesis? What is the relation between insulin action and doping? How can adapter molecules “recognize” and bind phosphotyrosine residues? What is a MAP kinase and what are the major substrates? How can a MAP kinase be activated due to the action of an extracellular growth factor? What is an oral glucose tolerance test and how does it work? What are the role of 14-3-3 proteins in the activation of the ERK pathway? How can the ERK pathway contribute to enhanced protein translation? What are Smad transcription factors and how can they specifically be activated? What are interleukin-6 effects? Discuss the role of an enzyme coupled receptor in the transduction of the interleukin-6 signal? What is the role of gp130 for the activation of STAT transcription factors? Which protein sequences determine whether a protein is imported or exported from the nucleus, and which proteins assist in this process? How can the IL-6 signal be switched off? What is the role of the glycogen synthese kinase-3 in the Wnt signal transduction pathway? How can proteins be degraded after they became phosphorylated; describe the detailed mechanism?