bio

Start Studying!

Terms

undefined, object

copy deck

transfer RNA (tRNA): Small RNA molecules that carry amino acids to the ribosome for polymerization into a polypeptide. During translation the amino acid is inserted into the growing polypeptide chain when the anticodon of the tRNA pairs with a codon on the mRNA being translated.
operator region: DNA region at one end of an operon that acts as the binding site for repressor protein. A DNA sequence that is recognized by a repressor protein or repressor-corepressor complex. When the operator is complexed with the repressor, transcription is prevented.
Poly-A-tail: a sequence of repeating adenosine ribonucleotides added to the 3' end of a newly transcribed pre- mRNA before it exits the nucleus. This modification can be up to 200-300 bases long and functions to increase the stability and translatability of the mRNA.
genotype: The specific allelic composition of a cell, either of the entire cell or more commonly for a certain gene or a set of genes. The genes that an organism possesses.
DNA fingerprinting: A method of identifying people based on the analyses of a persons satalite DNA (satalite DNA are small tandem repeats which make up a significant proportion of a cell's DNA and that is unique for each person
recombinant DNA: A novel DNA sequence formed by the joining, usually in vitro, of two non-homologous DNA molecules.
Topoisomerase: Enzymes of two types that can remove (or create) supercoiling in duplex DNA by creating transitory breaks in one (type I) or both (type II) strands of the sugar-phosphate backbone.
mutagen: physical or chemical agent that causes mutation
structural gene: gene en coding the amino acid sequence of a protein. Non-regulatory gene.
genetic code: set of rules giving the correspondence between codons in RNA and amino acids in proteins
5' cap: structure consisting of a 7-methylguanosine (m7G) residue attached backwards (i.e., 5' to 5') by a triphosphate linkage to the 5' end of primary mRNA transcripts in eukaryotes. In addition, the first and, in some cases, second nucleotide of the mRNA are methylated at the 2' position of the ribose residue. The 5' cap protects the mRNA from attack by 5' exonucleases and also functions in the recognition of the mRNA by ribosomes.
lytic cycle: reproductive cycle of phage T2 which results in the lysis (breaking open) of the host cell and the release of viruses produced in the cell
reverse transcriptase: An enzyme, requiring a DNA primer, that catalyzes the synthesis of a DNA strand from an RNA template. An enzyme that can use RNA as a template to synthesize DNA
protein synthesis: The process in which individual amino acids, whether of exogenous or endogenous origin, are connected to each other in peptide linkage in a specific order dictated by the sequence of nucleotides in dNA; this governing sequence is conveyed to the synthesizing apparatus in the ribosomes by mRNA, formed by base-pairing on the DNA template. A process where information is taken from DNA to acts as a blue print for creating a particular protein that is in demand by the body. This blueprint will allow the construction of the protein with the various materials required in its production. Pro.
One-gene-one-enzyme hypothesis: Hypothesis of Beadle and Tatum that one gene controls the production of one enzyme. Later modified to the concept that one cistron controls the production of one polypeptide
exons: coding regions; parts of a gene that are expressed as amino acids
Lac operon: An inducible operon including three loci involved in the uptake and breakdown of lactose in Escherichia coli.
gene: a discrete unit of hereditary information consisting of a specific nucleotide sequence in DNA (or RNA in some viruses); most of the genes of a eukaryote are located in its chromosonal DNA; a few are carried by the DNA of mitochondria and chloroplasts
ribosomal RNA: (rRNA) kind of RNA that makes one out of two subunits in a ribosome
GTP: A nucleotide composed of guanine, ribose, and three linked phosphate groups. It is incorporated into the growing RNA chain during synthesis of RNA and used as a source of energy during synthesis of proteins
RNA polymerase: transcription enzyme in which RNA nucleotides are linked
one-gene-one-polypeptide hypothesis: A revision of the one gene, one enzyme hypothesis.
Frameshift Mutation: The insertion or deletion of a nucleotide pair or pairs, causing a disruption of the translational reading frame.
inducible enzymes: an enzyme that can be detected in a growing culture of a microorganism, after the addition of a particular substance (inducer) to the culture medium, but was not detectable prior to the addition and can act on the inducer
restriction fragment length polymorphisms: (RFLPs) variation in DNA fragment banding patterns of electrophoresed restriction digests of DNA from different individuals of a species. Often due to the presence of a restriction enzyme cleavage site at one place in the genome in one individual and the absence of that specific site in another individual.
restriction enzyme: An endonuclease that will recognize a specific target nucleotide sequence in DNA and break the DNA chain at the target; a variety of these enzymes are known, and they are extensively used in genetic engineering.
semiconservative replication: The mode by which DNA replicates. Each strand acts as a template for a new double helix. The established model of DNA replication in which each double-stranded molecule is composed of one parental strand and one newly polymerized strand.
regulatory gene: A gene primarily involved in controlling another (structural) gene. Genes that are involved in turning on or off the transcription of structural genes.
sticky end: A protruding, single-stranded nucleotide se-quence produced when a restriction endonuclease cleaves off center in its recognition sequence
Carcinogens: An agent (chemical or radiation) that causes cancer.
Transposons: "jumping genes" A mobile piece of DNA that is flanked by terminal repeat sequences and typically bears genes coding for transposition functions.
Okazaki Fragments: Segment of newly replicated DNA produced during discontinuous DNA replication.
conjugation: union of cells and DNA transfer between them (Latin word conjugatus meaning united)
virus: particle consisting of a nucleic acid (RNA or DNA) genome surrounded by a protein coat (capsid) and sometimes also a membrane, which can replicate only after infecting a host cell. A virus particle may exist free of its host cell but is incapable of replicating on its own
transcription: transfer of DNA into an RNA molecule
RNA Primase: An enzyme that creates an RNA primer for initiation of DNA replication.
binary fission: The process in which a parent cell splits into two daughter cells of approximately equal size. Simple cell division in single-celled organisms.
elongation: parameter indicating the degree to which the cross-section of a toroidal plasma is non-circular. Kappa=b/a, where b and a are the vertical and horizontal minor radii. as kappa is increased, the confinement in relation to the total current improves, but the plasma also becomes more and more unstable to vertical displacements. a circular plasma has kappa of 1, a common value for elongated plasmas is 1.7, and the absolute limit is probably around 2.
corepressor: The metabolite that when bound to the repressor (of a repressible operon) forms a functional unit that can bind to its operator and block transcription.
RNA processing: A series of enzymatic reactions that convert the primary transcript to a mature functional molecule. Processing includes: base modification, sugar modification, pyrimidine ring rearrangements, formation of helices and tertiary conformations, additions to the 5′- and 3′-termini, specific exonucleolytic and endonucleolytic cleavages, complex cleavages with splicing and the formation of RNA-protein complexes. The number, type and order of the processing events varies with the RNA species
deletion: Loss of a DNA (chromosome) segment from a chromosome with often with disastrous effects.
episomes: A genetic element in bacteria that can replicate free in the cytoplasm (has a different number of copies) or can be inserted into the main bacterial chromosome and replicate with the chromosome. Plasmids are an example.
initiation: The first stage of tumour induction by a carcinogen; subtle alteration of cells by exposure to a carcinogenic agent so that they are likely to form a tumour upon subsequent exposure to a promoting agent (promotion
prophage: Phage DNA INSERTED BY GENETIC RECOMBINATION INTO THE DNA of a prokaryotic chromosone
DNA lisage: enzyme that links (ligates) the pieces together into a single DNA strand
Lagging Strand: In DNA replication, the strand that is synthesized apparently in the 3' to 5' direction, but actually in the 5' to 3' direction by ligating short fragments synthesized individually. Strand of DNA being replicated discontinuously.
lysogenic cycle: viral DNA replication occurs without destroying the host cell
helicase: A protein that unwinds DNA at replication forks.
translation: the transfer of information in the RNA into a protein
Histone: A type of basic protein that forms the unit around which DNA is coiled in the nucleosomes of eukaryotic chromosomes. Arginine and lysine rich basic proteins making up a substantial portion of eukaryotic nucleoprotein.
aminoacyl-tRNA: Transfer RNA ( tRNA) molecule with its cognate amino acid attached.
RNA Primer: An enzyme that creates an RNA primer for initiation of DNA replication.
transduction: transfer of a bacterial gene by a phage
Trp operon: tryptophan binds to the repressor protein and enables it to repress gene transcription.
introns: internal noncoding regions in most genes of plants and animals
phages: bacterial viruses "eaters"
Leading Strand: Strand of DNA being replicated continuously. In DNA replication, the strand that is made in the 5' to 3' direction by continuous polymerization at the 3' growing tip.
replication fork: The point at which the two strands of DNA are separated to allow replication of each strand
nucleotides: Subunit that polymerizes into nucleic acids (DNA or RNA). Each (word) consists of a nitrogenous base; a sugar; and one to three phosphate groups.
promoter region: A regulatory region a short distance upstream from the 5' end of a transcription start site that acts as the binding site for RNA polymerase. A region of DNA to which RNA polymerase binds in order to initiate transcription.
euchromatin: A chromosome region that stains poorly or not at all; thought to contain the normally functioning genes. Region of eukaryotic chromosome that is diffuse during interphase. Presumably the actively transcribing DNA of the chromosomes.
repressor protein: The protein product of a regulator gene that acts to control transcription of inducible and repressible operons. A molecule that binds to the operator and prevents transcription of an operon. Generally any molecule that can reversibly inactivate a gene.
mutation: any change in the nucleotide sequence of DNA
termination: stop of mRNA synthesis (i.e., transcription) at the terminator site
DNA polymerases: enzymes that link DNA nucleotides to a growing daughter strand that only add nucleotides to the 3' end of the strand, never to the 5' end
retrovirus: An RNA virus that replicates by first being converted into double-stranded DNA by reverse transcriptase.
heterochromatin: Densely staining condensed chromosomal regions, believed to be for the most part genetically inert. chromatin that remains tightly coiled (and darkly staining) throughout the cell cycle.
nucleosomes: A nu body; the basic unit of eukaryotic chromosome structure; a ball of eight histone molecules wrapped about by two coils of about 220 base pairs of DNA. Arrangement of DNA and histones forming regular spherical structures in eukaryotic chromatin.
Insertion: Gain of a DNA (chromosome) segment from a chromosome often with disastrous effects.
repressible enzymes: An enzyme whose production is generally continuous but can be halted if a particular substance is present in concentrations greater than normal
provirus: A virus chromosome integrated into the DNA of the host cell.
Single Stranded DNA binding proteins: Protein that binds to single-stranded DNA usually near the replication fork to stabilize the single strands.
bacteriophages: bacterial viruses "bacteria eaters"
transformation: uptake of foreign DNA from the surrounding environment
Polymerase chain reaction: (PCR) A powerful method for amplifying specific DNA segments which exploits certain features of DNA replication. For instance replication requires a primer and specificity is determined by the sequence and size of the primer. The method amplifies specific DNA segments by cycles of template denaturation; primer addition; primer annealing and replication using thermostable DNA polymerase. The degree of amplification achieved is set at a theoretical maximum of 2^N, where N is the number of cycles, eg 20 cycles gives a theoretical 1048576 fold amplification. In addition to primers and DNA polymerase, PCR reactions must contain template DNA (the DNA to be amplified) and the DNA "building blocks", deoxynucleotide triphosphates (dNTPs, which include dATP, dTTP, dGTP, and dCTP).
envelop: That which envelops, wraps up, encases, or surrounds; a wrapper; an inclosing cover; especially, the cover or wrapper of a document, as of a letter
dimer: a molecule which consists of two similar (but not necessarily identical) subunits. The term could also be used as a verb referring to the act of the two subunits coming together to (word)
gel electrophoresis: A research technique used to separate molecules (or fragments of a molecule) according to size. Upon electrical stimulation, smaller fragments of a molecule will move faster through the gel than larger fragments. The process is typically done to separate DNA fragments after the DNA has been cut with restriction enzymes.
messenger RNA: (mRNA) kind of RNA that encodes amino acid sequences; conveys genetic information from DNA and the message in it is then translated into polypeptides
Heterogenous nuclear RNA: The original RNA transcripts found in eukaryotic nuclei before post-transcriptional modifications. A diverse assortment of RNA types found in the nucleus, including mRNA precursors (pre-mRNA) and other types of RNA. Abbreviated hnRNA.
Small nuclear ribonucleicproteins (snRNPs): (RNA plus protein) particle. Component of the spliceosome, the intron-removing apparatus in eukaryotic nuclei.
excision repair: A process whereby cells remove part of a damaged DNA strand and replace it through DNA synthesis using the undamaged strand as a template. The repair of a DNA lesion by removal of the faulty DNA segment and its replacement with a new segment.
substitution: replacement of one nucleotide with another
Complemetary DNA: (cDNA) Synthetic DNA reverse transcribed from a specific RNA through the action of the enzyme reverse transcriptase. DNA synthesized by reverse transcriptase using RNA as a template.

Start Studying!

Deck Info

Number of cards 84