My Dog is Broken Assignment PDF

Preview

Summary

Participation Assignment
Dr. Alex Pettit...

Description

My Dog is Broken! A Case Study in Cell Signaling Assignment 1 Review Email I and then write an email to Tess identifying the first messenger that starts the signal transduction in the smooth muscle cell, the likely second messenger, and finally the cellular response caused by the cell signaling cascade. Explain why the arrows go from small to bigger. Also identify whether the receptor that starts the cell signaling pathway is in the plasma membrane or intracellular. From: Melody Mikelson [email protected] Sent: Wednesday, November 29, 2006 12:18 pm To: Tessa Wright [email protected] Subject: Cell signaling pathway analysis The first messenger that triggers signal transduction in the smooth muscle cell is nitric oxide and the second messenger is cyclic GMP or cGMP. The cellular response caused by the cell signaling cascade is relaxation, thus allowing for blood flow followed by an erection. The sizing of the arrows in the diagram is indicative of the amplification of the signalling pathway. Also note that the receptor that starts the signaling pathway, guanylyl cyclase, is located in the plasma membrane. Assignment 2 Review Email II and then answer the following questions: . Melody said that ginseng enhances erection. What effect would you expect ginseng to have on nitric oxide? Why? . Knowing that Melody said Viagra also enhances erection, what effect would you expect it to have on PDE? Why? . If neither chemical works what protein(s) would you suspect is “broken”? Since ginseng acts on nitric oxide to promote an erection, it likely activates the production of NO, thus leading to the promotion of the overall cascade as well. Viagra on the other hand likely inhibits PDE since PDE typically breaks down cGMP which is necessary for relaxation. If neither chemical work, the proteins that are likely “broken” are the ones after cGMP such as PKG or phosphor-proteins.

Regulates dilation + constriction of SM 1st messenger: nitric oxide Intracellular receptor: guanylyl cyclase -Takes GTPCyclic GMP -Activates protein kinase  Relaxation, more BF, erection

Sizes of arrows, larger: signal amplification Ginseng acts through NO -Increase production of NO Viagra acts through PDE -Phosphodiesterase inhibitor (typically to shut down) -PDE5 is and enzyme that breaks down cGMP PKg not activated -Inhibits the inhibitor If neither works -PKg might be broken -Anything downstream...