1. With the aid of diagrams describe the phospholipase C signalling pathway from ligand binding to intracellular effects (55%). Explain how G proteins AND kinases act as switches in the pathway (45%).
Many G protein coupled receptors exert the effects by G proteins.This activates the plasma membrane enzyme PLC phospholipase.The phospholipase cleaves Pip2 to generate IP3 and DAG.DAG molecule is attached tothe plasma membrane whereas IP3 molecule is released in the cytosol and will bind to the calcium gated channel and will cause the release of calcium from the endoplasmic reticulum.The G proteins contains alpha,beta and gamma subunits which when inactivated in the absence of the signal whereas in presence of signals the alpha subunit bounds to the GTP and is released from the beta and gamma subunit and stimulate the downstream signalling. There are GTPases which hydrolyses the GTP from alpha subuit and then the alpha subunit is again attached to beta and gamma subunit and is inactivated.Therefore acts as switches.
1. With the aid of diagrams describe the phospholipase C signalling pathway from ligand binding to...
une sequence of events involved in the cAMP second messenger system: a) Ligand binding to receptor > activate G protein > activate phospholipase C> increase intracellular CAMP > activate protein kinase A > phosphorylate proteins Ob) Ligand binding to receptor > activate G protein > activate phospholipase C> increase intracellular CAMP> activate protein kinase C > phosphorylate proteins c) Ligand binding to receptor > activate G protein > activate Adenylate cyclase > increase intracellular CAMP > activate protein kinase A...
-Trace the general mechanism by which a signal transduction pathway occurs (i.e. from signaling molecule to response) Describe the two ways in which signaling proteins act as molecular switches -Which amino acid residues do kinases typically add phosphate groups? Distinguish between the two types of G proteins -What proteins regulate GTP-binding protein (G proteins) in terms of activation and inactivation? - Distinguish between the three main classes of cell surface receptors. -Trace the general mechanism by which a signal transduction...
A) Draw and describe the Wnt signal transduction pathway i) with and ii) without ligand binding. Follow the molecules from the receptor, all the way into the nucleus. B) Summarize the formation of the dorsal axis in the Xenopus embryo beginning with the oocyte and proceeding through to the late blastula. Indicate where Wnt signaling is and is not activated. C) Explain the changes in gene expression that occur after Wnt activation and how these affect organizer genes and gastrulation....
or each of the following sentences, select the best word or phrase from the list below to fill in the blanks ot all words or phrases will be used; each word or phrase should be used only once 38. (3) An extracellular signal molecule can act to change a cell's behavior by acting through cell that control intracellular signaling proteins. These intracellular proteins that bring surface signaling proteins ultimately change the activity of about cell responses. Intracellular signaling proteins can...
related to insulin signaling This is related to insulir cell signaling 1) Describe the steps between the binding of an insulin molecule at the surface and the activation of the effector PI3K of the target cell 2) How does the action of the insulin receptor differ from other ligands that act by means of receptor tyrosine kinases? 3) What is the relationship between type 2 diabetes and insulin production? How is it that a drug that increases insulin sensitivity might...
1. The Hill Equation a) Derive the Hill Equation for a protein binding a single ligand (i.e. the reaction P + PL) and explain how a plot will appear. Derive the Hill Equation for a dimeric protein that simultaneously binds two ligands (i.e. the reaction: P2 2L- P2L2) and explain how a plot will appear. Explain what is problematic about the reaction shown in question b) L b) c) 1. The Hill Equation a) Derive the Hill Equation for a...
1. Suppose you modify a ligand to increase its ability to hydrogen bond with residues in the protein’s active site. Will this increase the binding affinity of that ligand to the protein. Explain your answer. 2. Describe how you know if a molecule is a bad choice for a substrate from PyRx results. Include one structural and one free energy argument.
PLEASE ANSWER ALL THE QUESTIONS IN EACH PART. THANK YOU! 1. (14pts) A. What are the functions of the signal recognition particle (SRP) and translocon in protein transport to the ER? SRP Translocon B. How does the translocon determine which orientation to insert membrane proteins? C. How do budding & fusion affect the orientation of integral membrane proteins during vesicle transport? D. Consider a ligand-gated ion channel at the plasma membrane that binds to ligands in the cytoplasm. From a...
9. What happens when a trimeric G a. Ga separates from b. GB separates from the GaG protein is activated by the GpGy dimer dimer d. Ga, Gp, and Gy separate from each other e. The trimeric G protein localizes to the c. Gy separates from the GaGß dimer t nuceus se the folowing list to answer questions 10-13.Answers can be used more than once a. Endocytosis followed by degradation in lysosomes tqitination mediated by SOCS followed by degradation by...
1. A biochemist is attempting to separate a DNA-binding protein (protein X) from other proteins in a solution. Only three other proteins (A, B, and C) are present. The proteins have the following properties: pl (isoelectric point) Size Mr Bind to DNA? protein A 7.4 protein B 3.8 protein C 7.9 protein X7.8 82,000 21,500 23,000 22,000 yes yes no yes What type of protein separation techniques might she use to protein X from the other proteins. Give a flow...