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
_____ maintain the length of telomeres. It binds and extends the three prime end, then DNA polymerase comes in and fill the gap.
Telomerases
A type of cancer caused by inherited defects in the mismatch repair protein complex is called____. Telomerase activity is a hallmark of cancer. It allows cancer cells to essentially be ____.
Hereditary non-polyposis colon cancer (HNPCC)
Immortal
_____ drugs tend to target DNA replication. Cancer cells are rapidly dividing cells, these replication, inhibiting drugs will target cancer cell more often than regular cells. However, red and white blood cells and skin cells do replicate fast and are affected by cancer drugs.
Cancer
