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Flashcards in Lecture 15 Deck (12)
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1
Q

DNA ligase

A

A linking enzyme essential for Dna replication; catalyzes the covalent bonding of the 3’ end of one dna fragment to the 5’ end of another DNA fragment.

2
Q

DNA polymerase

A

An enzyme
that catalyzes the elongation of new
DNA (for example, at a replication fork) by
the addition of nucleotides to the 3? end of
an existing chain. There are several different
DNA polymerases; DNA polymerase III and
DNA polymerase I play major roles in DNA
replication in E. coli.

3
Q

helicase

A

An enzyme that untwists the double
helix of DNA at replication forks, separating
the two strands and making them available
as template strands.

4
Q

lagging strand

A

A discontinuously synthesized
DNA strand that elongates by means
of Okazaki fragments, each synthesized in a
5?S 3? direction away from the replication
fork.

5
Q

leading strand

A

The new complementary
DNA strand synthesized continuously along
the template strand toward the replication
fork in the mandatory 5?S 3? direction.

6
Q

mismatch repair

A

The cellular process that
uses specific enzymes to remove and replace
incorrectly paired nucleotides.

7
Q

nuclease

A

An enzyme that cuts DNA or RNA,
either removing one or a few bases or hydrolyzing
the DNA or RNA completely into
its component nucleotides.

8
Q

origin of replication

A

Site where the replication
of a DNA molecule begins, consisting
of a specific sequence of nucleotides.

9
Q

primase

A

An enzyme that joins RNA nucleotides
to make a primer during DNA replication,
using the parental DNA strand as a
template.

10
Q

primer

A

A short stretch of RNA with a free 3?
end, bound by complementary base pairing
to the template strand and elongated with
DNA nucleotides during DNA replication.

11
Q

replication fork

A

the “fork in the road” of DNA replication

12
Q

telomere

A

The ends of eukaryotic chromosomal DNA molecules, the telomeres, have special nucleotide sequences