Replicating The Genome Flashcards
Genome replication occurs in the ___ phase exactly once every cell cycle
S
The two strands of a DNA double helix are always ______ of each other
Complementary
New DNA strands are synthesized always in the ___ prime to ___ prime direction by _____ polymerases
5
3
DNA
DNA polymerase will read the template strand in the ____ prime to ____ prime direction
3
5
One form of incorrect base pairing that can occur during DNA replication is a rare ____ form of cytosine binds with A (instead of T). Rapid ____ _____ of the C to its normal state destroys its base pairing with A.
Tautomeric
Tautomeric shift
DNA polymerase has ______ abilities to catch errors. DNA replication polymerases have 3’ to 5’ (backwards) _____ exonuclease activity.
Proofreading
Proofreading
New nucleotides are added to the 3’ ____ end of the ____ strand.
OH
Primer
The error rate in DNA polymerase is _____ in 100,000 nucleotides. With exonucleolytic proofreading, there is a ___ probability that the error will be detected.
1
99%
The ending error detection rate is only one in ______ nucleotides.
10,000,000,000
DNA replication occurs in ___ phase and takes about ___ hours.
S
8
Multiple ____ __ ____ initiate DNA replication. The origin strand separates from the daughter strand creating a ____. The ends of the bubble, where replication occurs is called the replication ____.
Origins of replication
Bubble
Replication fork
The ____ strand is synthesized continuously from 5’ to 3’ as DNA synthesis progresses. The ____ strand is synthesized discontinuously by a back stitching mechanism in small ____ ____.
Leading
Lagging
Okazaki fragments
____ ____ which is the key proteins that separates DNA parental strands, hydrolyzing ATP for energy. DNA helixes can move in the ___ to ___ direction as well as the ___ to ___ direction.
DNA helicase
5’ to 3’
3’ to 5’
Modifications of the ____ tail regulates, chromatin structure. _____ at lysine and _____ at lysine and arginine residues, weekends DNA histone interactions and supports transcription. ____ at serine and ____ at cytosines condenses DNA and promotes gene silencing.
Histone
Acetylation
Methylation
Phosphorylation
Methylation
DNA wraps and unwraps around ____ several times per second. ATP dependent chromatin remodeling complex of proteins bind to the DNA and the histone core catalyzing ____ ____ to make a DNA available.
Nucleosome
Nucleosome sliding
DNA polymerase cannot start DNA synthesis de novo, they need a base paired ____ ____with a free 3’-OH end. This primer is synthesized by ____, a DNA directed RNA polymerase.
RNA primer
Primase
For the leading strand primase lays down an RNA primer only ____. For the lagging strand, primase has to lay down the RNA primer for every ____ ____.
Once
Okazaki fragment
The RNA primer is removed and replaced with DNA by DNA polymerase and sealed with a ______.
Ligase
Single strand ____ _____ ____ will bind to DNA and keep it from tangling.
Binding protein monomers
As the DNA is unzipped, tension is increased. _______ cuts, one strand of a DNA double helix , relaxation occurs, and then the cut strand is reannealed. _____ cut both strands of a DNA double helix passes another unbroken DNA helix through it and then reanneals the cut strand.
Type I topoisomerase
Type II topoisomerase
The broad-spectrum fluoroquinolone antibiotics act by disrupting the function of bacterial _______.
Type II topoisomerases
Peripheral heterochromatin on the border of the nucleus is replicated ____ in S phase.
Later
____ are replicated late in S phase because they have TTAGGG repeats and are tightly wound (heterochromatin)
Telomeres
There is a small portion of the lagging strand at the end that cannot be replicated resulting in the shortening of _____ with every cell division. At the three prime end of the parental strand, there is no way to add nucleotides after the RNA primer is removed.
Telomeres
