Wednesday, January 27, 2016

Wednesday January 27th - DNA replication Activity and Wrap Up

Well...... TODAY was certainly interesting.  FIRST you came into the classroom looking a little different than normal..... 


It SORT of looked like a dance floor...... which would not be out of the realm of possibilities in this class.. But.... ALAS.... It was to go through DNA replication!

Our Goals have not changed - they are still what we had been focusing on since Monday.  Reminders are pretty much the same as well.
BEFORE we got into "acting out" DNA replication - we started with the following Daily Questions.  The first two are really just an algebra equation (and you thought you would NEVER use algebra outside of math class!!)
THEN......  since I am noticing that this concept of DNA replication being semi-conservative being a relatively difficult concept to grasp I have added one MORE activity to the mix.  We have watched animations of it online.  We have draw out and colored DNA strands.  We have used the K'nex models... and NOW....  we ACTED OUT DNA replication.   It was an interesting task for sure :)

FIRST - we created the "original" DNA sequence (the two "parent" strands)

In this case it was Nucleotides that were on black paper.

Next up..... Our DNA HELICASE!!!!  Sporting their pair of scissors to "snip through" the hydrogen bonds!
The next scene includes another set of important characters....  DNA polymerase.  These guys showed up with balloons on their heads because... well......... why NOT????

What did they do??  They added new nucleotides to either side of the parent DNA

End Result????













TWO genetically identical DNA molecules!!  Each one of the DNA molecules contains one "Parent" strand and one "Daughter" strand.   This is what is meant by Semi-conservative.

What does this look like in the cell?
If you check out the following video from 1:40 - 2:50 you will see this "machinery" at work.
The final part of DNA replication that I wanted you to be aware of was the differences between DNA replication in prokaryotic cells vs eukaryotic cells.  SINCE  prokaryotic DNA is packaged differently AND is found in the cytoplasm - DNA replication will proceed a bit differently.

Eukaryotic DNA, though, has it MUCH harder since there is MUCH more DNA.  So this is a little about that.
Finally.......  most classes had a little extra time sooo...... check out the new song I found for you guys ;)

DONE with DNA Replication!!!  Now onto Mitosis starting tomorrow :)

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