Events of the Past Week
During the course of the week, we spent two days learning about the contributions of Frederick Griffith, Oswald Avery, Alfred Hershey and Martha Chase, Erwin Chargaff, Rosalind Franklin, Maurice Wilkins, James Watson, Francis Crick, and Arthur Kornberg in the discovery of the structure of DNA. If you would like to learn about their contributions yourself, this is the website we used: http://www.dnai.org/lesson/go/9109/7537. It is really a neat interactive with interviews with many of the scientists who contributed something to the discovery. On Wednesday, we discussed the project and I lectured to the students about how it is that DNA replicates itself. This began our study of what Francis Crick called "The Central Dogma of Molecular Biology". Ask your children to explain what that is to you - they should be able to show you a quick diagram of it from their notes. On Thursday and Friday, we learned about the process of protein synthesis through a hands-on laboratory that was created by Kim Foglia - a wonderful biology teacher in New York. I wish I could take credit for the lab, but I can't! The students are finishing up the summary questions from this lab for homework this weekend. I took a few pictures in class of some students in action making their DNA strand, pairing up the proper mRNA bases with it, and then finally creating their protein using the instructions in the mRNA molecule that they decoded.
Dave is deep in thought here!
Hannah and Olivia really enjoyed this project!
This week we will begin by learning about mutations and the potential impact of mutations on an organism. This will be done with an activity I created last year after learning about a breed of cattle called the Belgian Blue. If you have never seen one, do a google image search for them - I promise you will be amazed! Tuesday through Thursday of this week we will spend our time learning about how molecular biologists are able to manipulate DNA by cutting it with special molecules called restriction enzymes. We will actually be taking DNA that has been cut into small pieces and using a technique called gel electrophoresis with it. Essentially, we'll run an electric current through a gel into which we have inserted some DNA, and then see how far the DNA travels in the gel. Different-sized DNA pieces will travel different distances. This experiment will lay the foundation for learning about how DNA fingerprinting works after final exams. On Friday, we will have a multiple choice test on the structure of DNA, DNA replication, the differences and similarities between DNA and RNA, the process of protein synthesis, and mutations. Also on Friday, I will be handing out the final exam review sheet. It is available already on my website for any students (or parents) who want to look at it before then.
For anyone interested in the Advanced Placement program, its history, and where it is headed, there was an interesting article in the New York Times about the history of the AP Biology (which I teach) and AP US History (which I do NOT teach) programs. It also includes a discussion of the future of the AP Biology program. The changes discussed will impact the current group of freshman if they choose to take AP Biology their senior year. The college board is planning on those changes being put into place for the 2012-2013 school year, and I think the changes are for the best! Here is the link to the article: http://www.nytimes.com/2011/01/09/education/edlife/09ap-t.html?_r=2&ref=education
As always, please feel free to click the comments link below and make any comments or e-mail me at firstname.lastname@example.org if you have any questions.