In the first section of this page, you will write a daily summary of that day's class. For example in your chapter 2 blog, your first entry should be titled 9/3/10. You should then write a one or two paragraph summary of that day's lecture, outlining the major points. In the second section, you are required to add two items (link to a website, video, animation, student-created slide show, student-created PowerPoint presentation) and one journal article pertaining to a topic in this chapter. A one-paragraph summary must accompany each item describing the main idea and how it applies to the lecture topic. Please see the PBWorks help guide for assistance embedding video and other items directly in the page. I will also produce a how-to video on using tables to wrap text around items and other useful tips. Please see the syllabus for organization and grading details.
A. Daily Blog
9/22/10
We got a handout containing all 20 amino acids in their respective groups. Then we proceeded with talking about prokaryotic cells. then we defined a genome, which is all the genetic material in a cell, and a proteome, which is the proteins the cell produces (The proteins produced vary in multicellular organisms). Next we talked about the Endomembrane system. This part was pretty much review of A&P. The new part is protein trafficking. This is the process in which the cell directs where the proteins go. This can be done many ways. Some proteins have a signal on the amino acid chain that is recognized by another protein which directs the ribosomal complex to pause translation and to attach to the Rough ER before resuming. Some are translated fully in the cytoplasm and are shipped to their respective destinations. Those without signals are left in the cytoplasm. Lastly we examined the Pulse-chase experiment. This experiment was used to track the location of proteins to see if they followed a specific path. We were to choose a radioactive isotope that would mark only proteins. The choices were the isotopes of Carbon, Nitrogen, Oxygen and Sulfur. Carbon and oxygen were ruled out due to their presence in all macromolecules. Nitrogen would highlight the nucleus as well as proteins. So the only choice left was Sulfur.
9/24/10
Sadly there was more technological difficulties. We talked about the three different protein pathways that are involved in protein trafficking. Proteins follow one of these paths depending on their final destination. The pathways are: Endoplasmic comodification( or cotranslational sorting), Semiautonomous organelles( or posttranslational sorting) and cytoplasm. Those that go through the endoplasmic reticulum end up secreted out of the cell, in the membrane or in an organelle such as the lysosome. This requires the first 20 amino acids of the protein to be the Endoplasmic signal sequence that tells the cell to send the ribosome to the endoplasmic reticulum. The protein that recognizes the signalis called the Signal Recognition Particle or SRP. Those that go to the Semiautonomous organelles are fully translated in the cytoplasm but are kept unfolded by chaperone proteins until inside the organelle. Finally the last group of proteins are translated in the cytoplasm and left there to fold.
B. Useful Materials
Items:
http://www.foldrx.com/sciece-protein-trafficking.htm
This website talks about the diseases that are caused by protein trafficking which end up getting stuck in the ER and are degraded by some other protein and thus the protein doesn't do its job and a host of other problems start.
http://www.plantcell.org/cgi/content/full/11/8/1377
Some more stuff on protein trafficking
Article about Protein trafficking:
http://www.ncbi.nlm.nih.gov/pubmed/20846261
This article is about how if a nuclear receptor (KAP60 in this case) isoform is missing the protein that was destined to be in the nuclear envelope end up in the plasma membrane.
Comments (1)
Derek Weber said
at 1:36 am on Nov 23, 2010
Updated
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