Coiling
Briefly explain why it is important for DNA to condense (coil) itself within a cell
It would not fit inside otherwise
Why do we say DNA Replication is bi-directional, and where does it start?
Starts in the middle and heads in 2 directions
Term for "nucleotides with extra phosphate groups, making them charged"
nucleoside triphosphate
Synthesis of a new DNA strand (by adding nucleotides) always happens in the __ to __ direction
5' to 3'
True or False:
G being paired with T would be considered a 'mismatch error'
true
These proteins help the DNA strand coil up.
What are Histone Proteins?
What is the big difference between DNA Replication in Prok. and Euk. cells?
Prok. cells only have one origin of replication, while Euk. cells have multiple origins of replication.
General term for an enzyme that builds polymers
What is a polymerase?
This polymerase functions to build the new DNA strand
Polymerase III
Contains at least 130 different repair mechanisms in humans
Third Line and Beyond
*3rd contains 130*
The level of coiling which makes DNA inaccessible (although it can be disassembled as needed).
30nm Fibers
What type of model do we use for DNA Replication?
*bonus 200 if you know why it is named this*
semi-conservative model
It conserves one parental strand, and synthesizes a new daughter strand.
*Each strand serves as a template strand for building a compliment*
Function is to build RNA Primers
What is Primase?
This polymerase functions to replace the RNA nucleotides of primers with DNA nucleotides
Polymerase I
Why do chromosomes get shorter each time they are replicated?
*Bonus 150: What is the result of this?*
Inability to replace RNA primers at the end of the 'lagging strand'
*You're going to die!*
DNA double-helix that is wrapped around a core particle which causes further coiling
-made from histone proteins
Nucleosome
Why do 'replication origins' have large quantities of adenine (A) and thymine (T)?
easier to start unzipping because there are only 2 hydrogen bonds that need to be broken. Instead of breaking 3 with C and G.
links Okazaki Fragments together
What is Ligase?
*ligase links!*
What makes the 'lagging strand' more complex to build? What is the process?
'Primer' needs to be built first so that we can synthesize in the proper direction.
'Primer' is then removed and 'Okazaki Fragments' are joined together with 'ligase'.
DNA Polymerases proofread newly made DNA here
-some "spelling errors" still get past
Front line
How does a histone protein do its job? What type of bond happens and where?
Basic ionic bonds that aren't permanent
-Attach to phosphate groups on DNA.
The term for when "DNA latches on at replication fork, reels it in, and spits out a single-stranded DNA".
Replication Bubble
A continually repeating sequence that repeats at the end of the DNA strand to prevent losing DNA fragments during replication
*Bonus 200 if you give that sequence*
What is a telomere?
*TTAGGG*
1. What does hydrolyzing the 1st bond in nucleoside triphosphate give the energy for?
2. What does hydrolyzing the 2nd bond in nucleoside triphosphate give the energy for?
1. Gives the energy for Polymerase I to replace the RNA nucleotides of primers with DNA nucleotides.
2. Gives the 'G' to form phosphodiester bonds to build the new strand
Specialized enzymes remove and replace incorrectly paired nucleotides here
*Bonus 200: defects in mismatch repair enzyme can result in _______.*
Second Line
*Colon cancer*