Chapter 13 Vocab Flashcards
Antiparallel
Referring to the arrangement of the sugar phosphate backbones in a DNA double helix (thy run in opposite 5’ to 3’ directions)
Bacteriophage
A virus that infects bacteria, also called a phage
Chromatin
the complex of DNA and proteins that makes up eukaryotic chromosomes. When the cell is not dividing, chromatin exists in its dispersed form, as a mass of very long, thin fibers that are not visible with a light microscope
DNA Ligase
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
DNA Polmymerase
An enzyme that catalyzes the elongation of new DNA by the addition of nucleotides to the 3’ end of an existing chain. There are several different DNA polymerase, DNA polymerase 3 and DNA polymerase 1 play major roles in DNA replication in E. Colu
DNA Replication
The process by which a DNA molecule is copied, also called DNA synthesis
Double helix
The form of native DNA, referring to its 2 adjacent antiparallel polynucleotide strands wound around an imaginary axis into a spiral shape
Helicase
An enzyme that untwist the double helix of DNA at replication forks, separating the two strands and making them available as template strands
Lagging strand
A discontinuously synthesized DNA strand that elongates by means of Okazaki fragments, each synthesized in a 5 to 3 direaction awasy from the replication fork
Leading strand
The new complementary DNA strand synthesized continuously along the template strand toward the replication fork in the mandatory 5 to 3 direction
Mismatch repair
The cellular process that uses specific enzymes to remove and replace incorrectly paired nucleotides
Nuclease
An enzyme that cuts DNA or RNA, either removing one or a few bases or hydrolizing he DNA or RNA completely into its component nucleotides
Nucleoid
A nonmembrane enclosed region in a prokaryotic cell where it’s chromosome is located
Nucleotide excision repair
A repair system that removes and then correctly replaces a damaged segment of DNA using the undamaged strand as a guide
Okazaki fragment
A short segment of DNA synthesized awasy from the replication fork on a template strand during DNA replication. Many such segments are joined together to make up the lagging strand of newly synthesized DNA
Origin of replication
Site where he replication of a DNA molecule begins, consisting of a specific sequence of nucleotides
Phage
A virus that infects bacteria, also called a bacteriophage
Primase
An enzyme that joins RNA nucleotides to make a primer during DNA replication, using the parental DNA strand as a template
Primer
A short stretch of RNA with with a. Free 3’ end, bound by complementary base pairing to the template strand and elongated with DNA nucleotides during DNA replication
Replication fork
A y shaped region on a replicating DNA molecule where the parental strands are being unwound and new strands are being synthesized
Semi conservative model
Type of DNA replication in which the replicated double helix consists of one old strand, derived from the parental molecule, and one newly made strand
Single strand binding protien
A protein that binds to the unpaired DNA strands during DNA replication stabilizing them and holding them apart while they serve as templates for the synthesis of complementary strands of DNA
Telomerase
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Telomere
The tandemly repetitive DNA at the end of a eukaryotic chromosomes DNA molecule. Telomeres protect the organisms genes from being eroded during successive rounds of replication
Topoisomerase
A protein that breaks, swivels and rejoins DNA strands. During DNA replication, topoimerase helps to relieve strain in the double helix ahead of the replication fork
Transformation
The process by which a cell in culture acquires the ability to divide indefinitely, similar to the division of cancer cells, OR a change in genotype and phenotype due to the assimilation of external DNA by a cell, Whenb the external DNA is from a member of a different species, ransformation results in horizontal gene trasnfer
Virus
And infectious particle incapable of replicating outside of a cell, consisting of an RNA or DNA genome surrounded by a protein coat and, for some viruses, a membranous envelope
