Monday and Tuesday January 25th and 26th - DNA Replication in Detail

The past few days have been full of coloring and crash coursing it and K'nex modeling it.....   It's been pretty active in class these past two days learning about DNA replication.  The reminders and goals for both Monday and Tuesday were the same:

Yesterday was Day one of DNA replication in detail.  We started the class off with the following daily questions.   We spent a LOT of time on these and were very careful to draw out DNA replication.

I added one more drawing of this.  The thing to keep in mind here are the COLORS of the different DNA strands.  You will notice that at the END (the bottom two DNA molecules) - Each one is composed of one ORIGINAL DNA strand (The blue strand) and one NEW DNA strand (the green strand)

 That second question was really still referring to the the first question.  It is KEY to understand this concept of DNA replication being "semi conservative"!

We then got down a couple notes to prep us for another activity that we did today:

Today's Daily Questions went RIGHT along with these two slides and led us into an activity using the K'nex models.

First we acted like DNA HELICASE and "Unzipped the genes."  What does THAT mean????  Well FIRST we need to know what the "zipper" is made up of to begin with - The nucleotide strands are held together by HYDROGEN BONDS.  So the role of these Helicases are to break hydrogen bonds

Next up - We acted Like DNA POLYMERASE and started adding new nucleotides to either side at the "replication fork."  How did we KNOW what to add????  We used the base pairing rules A-T and C-G

and FINALLY..... We ended up with TWO IDENTICAL DNA Molecules - each consisting of one "Old" Strand (the gray backbone) and one "New" Strand (the yellow backbone)

Then you started on a worksheet to see how much of this you retained (and showed me that hopefully this time working with the K'nex models helped your comprehension of the subject more rather than take you back to your younger days of just building roller coasters with K'nex models....?!?!)

Here was the general concept of the worksheet