Chapter 13 Flashcards
Referring to the arrangement of the sugar phosphate backbones in a DNA double helix (they run in the opposite 5’—3’ directions)
Antiparallel
A virus that infects bacteria; also called a phage
Bacteriophage
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
Chromatin
In genetic engineering, a DNA molecule that can carry foreign DNA into a host cell and replicate there. They include plasmids
Cloning vectors
A linking enzyme essential for DNA replication; catalyzes the covalent bonding of the 3’ end of one DNA fragment (such as the Okazaki fragment) to the 5’ end of another DNA fragment (such as a growing DNA chain)
DNA ligase
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 n existing chain. There are several different DNA polymerases; DNA polymerase III and DNA polymerase I play major roles in DNA replication in E. Coli
DNA polymerase
The process by which a DNA molecule is copied; also called DNA synthesis
DNA replication
Determining the order of nucleotide based in a gene or DNA fragment
DNA sequencing
The form of native DNA, referring to its two adjacent antiparallel poly nucleotide strands wound around an imaginary axis into a spiral shape
Double helix
The less condensed form of eukaryotic chromatin that is available for transcription
Euchromatin
A technique for separating nuclei acids or proteins on the basis of their size and electrical charge, both of which affect their rate of movement through an electric field in a gel made of agarose or another polymer
Gel electrophoresis
The production of multiple copies of a gene
Gene cloning
The direct manipulation of genes for practical purposes
Genetic engineering
An enzyme that untwists the double helix of DNA at replication forks, separating the two strands and making them available as template strands.
Helicase
Eukaryotic chromatin that remains highly compacted during interphase and is generally not transcribed
Heterochromatin
A discontinuously synthesized DNA strand that elongates by means of Okazaki fragments, each synthesized in a 5’— 3’ direction away from the replication fork
Lagging strand
The new complementary DNA strand synthesized continuously along the template strand toward the replication fork in the mandatory 5’—3’
Leading strand
The cellular process that uses specific enzymes to remove and replace incorrectly paired nucleotides
Mismatch repair
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
Nuclease
A polymer (polynucleotide) consisting of many nucleotide monomers; serves as a blueprint for proteins and, through the actions of proteins, for all cellular activities. The two types are DNA and RNA
Nucleic acid
A non-membrane-enclosed region in a prokaryotic cell where it’s chromosome is located
Nucleoid
A repair system that removed and then correctly replaced a damaged segment of DNA using the un damaged strand as a guide
Nucleotide excision repair
A short segment of DNA synthesized away 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
Okazaki fragment
Site where the replication of a DNA molecule begins, consisting of a specific sequence of nucleotides
Origin of replication
See polymerase chain reaction
PCR
A virus that infects bacteria ; also called a bacteriophage
Phage
A small, circular, double-stranded DNA molecule that Carrie’s accessory genes separate from tHose of a bacterial chromosome; in DNA cloning, can be used as a vector carrying up to about 10,000 base pairs (10 kb) of DNA
Plasmid
A small, circular, double-stranded DNA molecule that Carrie’s accessory genes separate from tHose of a bacterial chromosome; in DNA cloning, can be used as a vector carrying up to about 10,000 base pairs (10 kb) of DNA
Plasmid
A technique for amplifying DNA in vitro by incubating it with specific primers, a heat-resistant DNA polymerase, and nucleotides
Polymerase chain reaction
An enzyme that joins RNA nucleotides to make a primer during DNA replication, using the parental DNA strand as a template
Primase
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
Primer
A DNA molecule made in vitro with segments from different sources
Recombinant DNA molecule
A Y-shaped region on a replicating DNA molecule where the parental strands are being unwound and new strands are being synthesized
Replication fork
An endonuclease (type of enzyme) that recognizes and cuts DNA molecule foreign to a bacterium (such as phage genomes). The enzyme cuts rapt specific nucleotide sequences (restriction sites)
Restriction enzyme
A DNA segment that results from the cutting of DNA by a restriction enzyme
Restriction fragment
A specific sequence on a DNA strand that is recognized and cut by a restriction enzyme
Restriction site
Type of DNA replication in which the replicated double helix consisted of one cold strand, derived from the parental molecule, and one newly made strand
Semiconservative model
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
Single-strand binding protein
A single-stranded end of a double-stranded restriction fragment
Sticky end
The tenderly repetitive DNA at the end of a eukaryotic chromosome’s DNA molecule. They protect the organism’s genes from being eroded during successive rounds of replication. See also repetitive DNA
Telomere
A protein that breaks, swivels and rejoins DNA strands. During DNA replication, it helps to relieve strain in the double helix ahead of the replication fork
Topoisomerase
(1) the process by which a cell in culture acquires the ability to divide indefinitely, similar to the division of cancer cells (2) a change in genotype and phenotype due to the assimilation of external DNA by a cell. When the external DNA is from a member of a different species, transformation results in horizontal gene transfer
Transformation
An infectious particle incapable of replicating outside of a cell, consisting of an RNA or DNA genome surrounded by a protein coat (capsid) and, for some, a membranous envelope
Virus
