Chapter 13 Vocab Flashcards
Referring to the arrangement of the sugar-phosphate backbones in a DNA double helix (they run in opposite 5? ? 3? directions).
Antiparallel
The form of native DNA, referring to its two adjacent antiparallel polynucleotide strands wound around an imaginary axis into a spiral shape.
Double helix
The process by which a DNA molecule is copied; also called DNA synthesis
DNA replication
1) The conversion of a normal animal cell to a cancerous cell. (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
A virus that infects bacteria; also called a phage.
Bacteriophages
A virus that infects bacteria; also called a bacteriophage
Phages
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 viruses, a membranous envelope.
Virus
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Base Pairing
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.
Semiconservative Model
Site where the replication of a DNA molecule begins, consisting of a specific sequence of nucleotides.
Origin of replication
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 enzyme that untwists the double helix of DNA at replication forks, separating the two strands and making them available as template strands.
Helicase
Single Strand Binding Proteins
SSB
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.
SSB - Single Strand Binding Proteins
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
Topoisomerase
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
An enzyme that joins RNA nucleotides to make a primer during RNA replication, using the parental DNA strand as a template
Primase
An enzyme that catalyzes the elongation of new DNA (for example at the 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
DNA Polymerases
The new complementary DNA strand synthesized continuously along the template strand toward the replication fork in the mandatory 5? ? 3? direction.
Leading strand
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
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 Fragments
A linking enzyme essential for DNA replication; catalyzes the covalent bonding of the 3’ end of one DNA fragment ( such as an okazaki fragment)
DNA Ligase
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 repair system that removes and then correctly replaces a damaged segment of DNA using the undamaged strand as a guide
Nucleotide Excision Repair
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.
Telomere
An enzyme that catalyzes the lengthening of telomeres in eukaryotic germ cells.
Telomerase
A non-membrane-bounded region in a prokaryotic cell where the DNA is concentrated.
Nucleoid
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
Eukaryotic chromatin that remains highly compacted during interphase and is generally not transcribed.
Heterochromatin
The less condensed form of eukaryotic chromatin that is available for transcription.
Euchromatin
The building block of a nucleic acid, consisting of a five-carbon sugar covalently bonded to a nitrogenous base and one or more phosphate groups.
Nucleotide
