Unit 7- Nucleid Acids Flashcards
the procedure of determining the order of nucleotides in a DNA section.
Base sequencing
a bacterial enzyme that catalyses the breaking and re-joining of bonds linking adjacent nucleotides in circular DNA to generate supercoiled DNA helices.
DNA gyrase
various enzymes that function in the replication and repair of DNA by catalysing the linking of nucleotides in a specific order, using single-stranded DNA as a template.
DNA polymerases
an enzyme involved in the initiation of DNA replication that catalyses the polymerization of short RNA primers on the template DNA.
DNA primase
the analysis of a small amount of genetic material used to identify multilocus DNA banding patterns that are specific to an individual is often used to provide evidence in criminal law cases; also called genetic fingerprinting.
DNA profiling
the process of making an identical copy of a DNA molecule, using existing DNA as a template for the synthesis of new DNA strands.
DNA replication
a prokaryote enzyme that unwinds the DNA helix at the replication fork, breaking the hydrogen bonds, to allow the resulting single strands to be copied.
Helicase
any of several small, basic proteins most commonly found in association with the DNA in the chromatin of eukaryotes.
Histone
a segment of a gene situated between exons that is removed before the translation of messenger RNA and does not function in coding for protein synthesis.
Intron
the strand of the DNA double helix that, because of its orientation that is opposite to the working orientation of DNA polymerase III, is synthesized in a series of short fragments known as Okazaki fragments.
Lagging strand
DNA strand being replicated by continuous polymerization at the 3′ growing tip.
Leading strand
the basic bead-like unit of DNA packing in eukaryotes, consisting of a sequence of DNA wound around a protein core composed of eight histones.
Nucleosome
the building blocks of a nucleic acid, consisting of a carbon sugar covalently bonded to a nitrogenous base and a phosphate group.
Nucleotides
a site on a DNA molecule at which the unwinding of the helices and synthesis of daughter molecules are both occurring during DNA replication.
Replication fork
copies of genes repeated one after another along a chromosome.
Tandem repeats
a region of repetitive nucleotide sequences at each end of a chromatid that is involved in the replication and stability of DNA molecules protecting the end of the chromosome from deterioration.
Telomere
an analytical method in which X-rays change direction on contact with matter, resulting in changes in radiation intensity, that is used to determine the three-dimensional arrangement of atoms.
X-ray diffraction
a segment of DNA or RNA that is complementary to a given DNA sequence and that is needed to initiate replication by DNA polymerase.
Primer
the only direction that DNA polymerase can synthesize DNA; it does so by adding nucleotides to the 3’ end of a DNA strand.
5’ to 3’
the modification of a strand of DNA after it is replicated, in which a methyl (CH3) group is added and is one of the methods used to regulate the expression of genes.
DNA methylation