Structure of DNA Flashcards
The strands are
anti parallel
Bases are stacked on one another, and is
stabilized by
van der Waals interaction
A process in which a DNA creates an identical copy of
itself
Replication
Replication follow what type of mechanism
Semiconservative Replication
Mechanism
cytosine and
guanine is connected by how many hydrogen bond
3
Adenine and thymine is connected by how many
hydrogen bonds
2
DNA
Replication phases
Initiation Elongation Termination
DNA replication starts at specialized sites
called origins of replication, and moves
away from the origin in both directions,
creating a
replication bubble
The ? strand is copied in a continuous manner
leading
The ? strand is copied in a discontinuous manner
Lagging
The Lagging strand is copied in a discontinuous manner, which
results to fragments created, known as
Okazaki fragments
Helicase harnesses chemical
energy from ?
ATP hydrolysis
protein that bind selectively to
ssDNA as soon as it forms, and
stabilizing and protecting it.
singlestrand DNA Binding
proteins
As the helicase
unwinds DNA, the
twist ahead of the
fork decreases in
tension. TRue or false
false
clockwise rotation right handed in negative supercoil
DNA Topoisomerase II
counterclockwise rotation left handed in positive supercoil
DNA Topoisomerase I
has the role of
synthesizing RNA primers
Primase
Prokaryotic Polymerase includes pol III and pol I. TRUE OR FALSE
TRUE
Eukaryotic Polymerase INCLUDES DNA Polymerase α and DNA Polymerase δ. true or false
true
Directs the synthesis of a new
DNA strand
DNA Polymerase δ
seals nicks and breaks in dsDNA molecules through
the formation of phosphodiester bonds between existing DNA
strands
DNA Ligase
Replication pattern used by most eukaryotic and bacterial DNA
Bidirectional Replication
Rolling Circle Replication
Pattern common among bacteriophage
maintains the length
of telomeres by addition of
guanine-rich repetitive sequence
Telomerase
Telomerase binds to ? of the telomere sequence along with RNA template
3 prime end
telomeres shorten as it cell divides. true or false
true
The mitochondria duplication
is ?
stochastic
there is
no control over which
particular copies are replicated
stochastic
The process of mitochondrial
replication is through
fission
Proofreading Mechanism in In prokaryotes
DNA Polymerase I
Proofreading Mechanism in Eukaryotes
DNA Polymerase δ
Large fragment in DNA Polymerase I called
Klenow fragment
small fragment in DNA Polymerase I has
exonuclease activity
All synthesis of nucleotide chains occurs in the what direction
5’-3’
The incoming nucleotide has a 5’ hydroxyl group on its sugar. true or false
false
The last nucleotide has a 3’ hydroxyl group on the sugar. true or false
true
leading strand direction
5’ to 3’
template strand direction
3’ to 5’
Okazaki fragments is usually how many nucleotides long
1000 - 2000
Unwinds parental double helix.
helicase
occurs when the two replication forks moving in opposite directions meet
termination
Termination site in Bacteria
ter
Binds nucleotides to form new strands
dna polymerase
Correctness of copied DNA
fidelity
how many nucleotides lost during each cell cycle
50
