6-2 Vocab Flashcards
Mismatch Repair
The cellular process that uses specific enzymes to remove and replace incorrectly paired nucleotides
Cloning Vector
In genetic engineering, a DNA molecule that can carry foreign DNA into a host cell and replicate there. Cloning vectors include plasmids
Heterochromatin
Eukaryotic chromatin that remains highly compacted during interphase and is generally not transcribed
Primase
An enzyme that joins RNA nucleotides to make a primer during DNA replication, using the parental DNA strand as a template
Single-strand Binding Proteins
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
Telomeres
The tandemly repetitive DNA at the end of a eukaryotic chromosome’s DNA molecule. Telomeres protect the organism’s genes from being eroded during successive rounds of replication. See also repetitive DNA
Polymerase Chain Reaction
A technique for amplifying DNA
in vitro by incubating it with specific primers,
a heat-resistant DNA polymerase, and
nucleotides
DNA Ligase
A linking enzyme essential for DNA replication; catalyzes the covalent bonding of the 3′ end of one DNA fragment (such as an Okazaki fragment) to the 5′ end of another DNA fragment (such as a growing DNA chain)
DNA Sequencing
Determining the order of nucleotide bases in a gene or DNA fragment
Recombinant DNA Molecule
A DNA molecule made in vitro with segments from different sources
Topoisomerase
A protein that breaks, swivels, and rejoins DNA strands. During DNA replication, topoisomerase helps to relieve strain in the double helix ahead of the replication fork
PCR
A technique for amplifying DNA in vitro by incubating it with specific primers, a heat-resistant DNA polymerase, and nucleotides
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
Restriction Enzymes
An endonuclease (type of enzyme) that recognizes and cuts DNA molecules foreign to a bacterium (such as phage genomes). The enzyme cuts at specific nucleotide sequences (restriction sites)
Gel Electrophoresis
A technique for separating nucleic 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
Helicases
An enzyme that untwists the double helix of DNA at replication forks, separating the two strands and making them available as template strands
Gene Drive
A process that biases inheritance such that a particular allele is more likely to be inherited than are other alleles, causing the favored allele to spread (be “driven”) through the population
Nucleoid
A non-membrane-enclosed region in a prokaryotic cell where its chromosome is located
Leading Strand
The new complementary DNA strand synthesized continuously along the template strand toward the replication fork in the mandatory 5’ to 3’ direction
Restriction Fragments
A DNA segment that results from the cutting of DNA by a restriction enzyme
