About this Series
- Lessons: 2
- Total Time: 0h 26m
- Use: Watch Online & Download
- Access Period: Unlimited
- Created At: 06/23/2009
- Last Updated At: 07/20/2010
This two part series starts off with Watson and Crick who also proposed a possible method of replication, which is a requirement for genetic material, in their article. This method, called the semi-conservative method, was just proposed, though, and untested. Meselson and Stahl devised a method to test the replication. There are three types of possible replication methods, conservative, semi-conservative, and dispersive. Professor Wolfe explains these three types of replication and the method of adding isotopes to bacteria that Meselson and Stahl used to test replication. He compares and contrasts the expected outcomes of each type of replication with the actual outcome that Weselson and Stahl found. This testing confirmed the semi-conservative method of DNA replication.
Part two continues with Meselson and Stahl determining that DNA is replicated using the semi-conservative method, which means that the DNA opens down the middle, and each side acts as a template for the new strand. But this answer only produces more questions. How does the polymerization of the new strand of DNA happen? Polymerization is an endemic process (meaning it requires energy), and not spontaneous. It also required joining of the sugar-phosphates, in addition to the nucleotides. Finally, it requires an enzyme, known as DNA polymerase. Professor Wolfe explains how triphosphate nucleotides make the polymerization process possible. These triphosphate nucleotides float freely within the nucleus of the cell, and each DNA base exists in a triphosphate nucleotide form. The energy that is released by the breaking of the triphosphate bond is what provieds the energy for the polymerization of DNA.
Taught by Professor George Wolfe, this lesson was selected from a broader, comprehensive course, Biology. This course and others are available from Thinkwell, Inc. The full course can be found at http://www.thinkwell.com/student/product/biology. The full course covers evolution, ecology, inorganic and organic chemistry, cell biology, respiration, molecular genetics, photosynthesis, biotechnology, cell reproduction, Mendelian genetics and mutation, population genetics and mutation, animal systems and homeostasis, evolution of life on earth, and plant systems and homeostasis.
About this Author
-
- Thinkwell
- 2174 lessons
- Joined:
11/13/2008
Founded in 1997, Thinkwell has succeeded in creating "next-generation" textbooks that help students learn and teachers teach. Capitalizing on the power of new technology, Thinkwell products prepare students more effectively for their coursework than any printed textbook can. Thinkwell has assembled a group of talented industry professionals who have shaped the company into the leading provider of technology-based textbooks. For more information about Thinkwell, please visit www.thinkwell.com or visit Thinkwell's Video Lesson Store at http://thinkwell.mindbites.com/.
Thinkwell lessons feature a star-studded cast of outstanding university professors: Edward Burger (Pre-Algebra through...
Lessons Included
Below are the descriptions for each of the lessons included in the series:
-
Biology: Replication: Meselson and Stahl
Watson and Crick also proposed a possible method of replication, which is a requirement for genetic material, in their article. This method, called the semi-conservative method, was just proposed, though, and untested. Meselson and Stahl devised a method to test the replication. There are three types of possible replication methods, conservative, semi-conservative, and dispersive. Professor Wolfe explains these three types of replication and the method of adding isotopes to bacteria that Meselson and Stahl used to test replication. He compares and contrasts the expected outcomes of each type of replication with the actual outcome that Weselson and Stahl found. This testing confirmed the semi-conservative method f DNA replication.
Taught by Professor George Wolfe, this lesson was selected from a broader, comprehensive course, Biology. This course and others are available from Thinkwell, Inc. The full course can be found at http://www.thinkwell.com/student/product/biology. The full course covers evolution, ecology, inorganic and organic chemistry, cell biology, respiration, molecular genetics, photosynthesis, biotechnology, cell reproduction, Mendelian genetics and mutation, population genetics and mutation, animal systems and homeostasis, evolution of life on earth, and plant systems and homeostasis.
-
Biology:DNA Polymerization-Triphosphate Nucleotide
Meselson and Stahl determined that DNA is replicated using the semi-conservative method, which means that the DNA opens down the middle, and each side acts as a template for the new strand. But this answer only produces more questions. How does the polymerization of the new strand of DNA happen? Polymerization is an endemic process (meaning it requires energy), and not spontaneous. It also required joining of the sugar-phosphates, in addition to the nucleotides. Finally, it requires an enzyme, known as DNA polymerase. Professor Wolfe explains how triphosphate nucleotides make the polymerization process possible. These triphosphate nucleotides float freely within the nucleus of the cell, and each DNA base exists in a triphosphate nucleotide form. The energy that is released by the breaking of the triphosphate bond is what provieds the energy for the polymerization of DNA.
Taught by Professor George Wolfe, this lesson was selected from a broader, comprehensive course, Biology. This course and others are available from Thinkwell, Inc. The full course can be found at http://www.thinkwell.com/student/product/biology. The full course covers evolution, ecology, inorganic and organic chemistry, cell biology, respiration, molecular genetics, photosynthesis, biotechnology, cell reproduction, Mendelian genetics and mutation, population genetics and mutation, animal systems and homeostasis, evolution of life on earth, and plant systems and homeostasis.
George Wolfe brings 30+ years of teaching and curriculum writing experience to Thinkwell Biology. His teaching career started in Zaire, Africa where he taught Biology, Chemistry, Political Economics, and Physical Education in the Peace Corps. Since then, he's taught in the Western NY region, spending the last 20 years in the Rochester City School District where he is the Director of the Loudoun Academy of Science.
Besides his teaching career, Mr. Wolfe has also been an Emmy-winning television host, fielding live questions for the PBS/WXXI production of Homework Hotline as well as writing and performing in "Football Physics" segments for the Buffalo Bills and the Discover Channel.
His contributions to education have been extensive, serving on multiple advisory boards including the Cornell Institute of Physics Teachers, the Cornell Institute of Biology Teachers and the Harvard-Smithsonian Center for Astrophysics SportSmarts curriculum project. He has authored several publications including "The Nasonia Project", a lab series built around the genetics and behaviors of a parasitic wasp.
He has received numerous awards throughout his teaching career including the NSTA Presidential Excellence Award, The National Association of Biology Teachers Outstanding Biology Teacher Award for New York State, The Shell Award for Outstanding Science Educator, and was recently inducted in the National Teaching Hall of Fame.
Supplementary Files:
- Once you purchase this series you will have access to these files:
Buy Now and Start Learning
Also from Thinkwell:
Link to this page
Copy and paste the following snippet:
I love the enthusiasm in this tutorial, it helped catch and keep my interest throughout. No mean feat at the moment as I am nursing a headcold and have the concentration of a goldfish, but this tutorial still managed to help me get my foggy head around the subject where my text book couldn't. The only reason it didn't score a five was because it left me hanging at the end...I hate movies that end on cliffhangers ;P ! Suppose I shall just have to purchase the next installment then, great sales technique!