GN terms 3

Consensus sequence (TATAAT) found in most bacterial promoters approximately 10 bp upstream of the transcription start site

Consensus sequence (TTGACA) found in many bacterial promoters approximately 35 bp upstream of the transcription start site

3' elongation

End of the polynucleotide chain where an OH group is attached to the 3'-carbon atom of the nucleotide

The 3' end of an intron where cleavage takes place in RNA splicing

Sequence of nucleotides at the 3' end of mRNA; Does not encode the amino acids of a protein but affects both the stability of the mRNA and its translation

Modified 5' end of eukaryotic mRNA, consisting of an extra nucleotide (methylated) and methylation of the 2' position of the ribose sugar in one or more subsequent nucleotides; Plays a role in the binding of the ribosome to mRNA and affects mRNA stability and the removal of introns

End of the polynucleotide chain where a phosphate is attached to the 5'-carbon atom of the nucleotide

The 5' end of an intron where cleavage takes place in RNA splicing

Sequence of nucleotides at the 5' end of mRNA; Does not encode the amino acids of a protein

Modified nucleotide, consisting of cytosine to which a methyl group has been added; Predominate form of methylation in eukaryotic DNA

11nm

30nm

Initial complex formed in the initiation of translation in bacterial cells; Consists of the small subunit of the ribosome, mRNA, initiator tRNA charged w/ fMet, GTP, and initiation factors 1, 2 and 3

Final complex formed in the initiation of translation in bacterial cells; Consists of the small and large subunits of the ribosome, mRNA, and initiator tRNA charged w/ fMet

300nm

Right-handed helical structure of DNA that exists when little water is present

Process by which a specific environment induces mutations that enable organisms to adapt to the environment

Purine base in DNA and RNA

One of several pathways by which a single pre-mRNA can be processed in different ways to produce alternative types of mRNA

Process by which a single pre-mRNA can be spliced in more than one way to produce different types of mRNA

Alu

Test in which special trains of bacteria are used to evaluate the potential of chemicals to cause cancer

Repeating unit of proteins; consists of an amino group, a carboxyl group, a hydrogen atom, and a variable R group

One of 3 sites in a ribosome occupied by a rTNA in translation. All charged tRNAs (with the exception of the initiator tRNA) first enter the A site in translation

Enzyme that attaches an amino acid to a tRNA. Each __ is specific for a particular amino acid

Sequence of 3 nucleotides in tRNA that pairs with the corresponding codon in mRNA in translation

Refers to a characteristic of the DNA double helix in which the two polynucleotide strands run in opposite directions

DNA sequence that confers the ability to replicate; contains an origin of replication

Bacterium or fungus that possesses a nutritional mutation that disrupts its ability to synthesize an essential biological molecule; cannot grow on minimal medium but can grow on minimal medium to which has been added the biological molecule that it cannot synthesize

Right-handed helical structure of DNA that exists when water is abundant; the secondary structure described by Watson and Crick and probably the most common DNA structure in cells

Complex of transcription factors, RNA polymerase, and other proteins that assemble on the promoter and are capable of initiating minimal levels of transcription

Chemical substance that has a structure similar to that of one of the four standard bases of DNA and may be incorporated into newly synthesized DNA molecules in replication

Mutation in which a single pair of bases in DNA is altered

DNA repair that first excises modified bases and then replaces the entire nucleotide

Replication at both ends of a replication bubble

Adenine nucleotide in nuclear pre-mRNA intons that lies from 18 to 40 nucleotides upstram of the 3' splice site

Haploid amount of DNA found in a cell of an organism

CAAT

Concept that genetic information passes from DNA to RNA to protein in a one-way information pathway

DNA sequence found in functional centromeres

Rules developed by Erwin Chargaff and his colleagues concerning the ratios of bases in DNA

Consists of a nucleosome and an H1 histone protein

Localized swelling of a polytene chromosome; a region of chromatin in which DNA has unwound and is undergoing transcription

Protein that plays a role in the folding and packing of the chromosome, revealed when chromatin is treated with a concentrated salt solution, which removes histones and some other chromosomal proteins

Cis-acting element

Cistron

Secondary structure common to all tRNAs

Sequence of 3 nucleotides that encodes one amino acid in a protein

Produced in replicative transposition, an intermediate structure in which two DNA molecules with two copies of the transposable element are fused

Concept that there is a direct correspondence between the nucleotide sequence of a gene and the continuous sequence of amino acids in a protein

The relation between the two nucleotide strands of DNA in which each purine on one strand pairs with a specific pyrimidine on the opposite strand (A pairs with T, and G pairs with C)

Type of transposable element in bacteria that consists of two insertion sequences flanking a segment of DNA

Expressed only under certain conditions

Comprises the most commonly encountered nucleotides found at a specific location in DNA or RNA

Conservative transposon

Constitutive Heterochromatin

Replication of the leading strand in the same direction as that of unwinding, allowing new nucleotides to be added continuously to the 3' end of the new strand as the template is exposed

Part of the bacterial RNA polymerase that, during transcription, catalyzes the elongation of the RNA molecule by the addition of RNA nucleotides; consists of four subunits; two copies of alpha, a single copy of beta, and a single copy of beta prime

Located immediately upstream of the eukaryotic promoter, DNA sequences to which the basal transcription apparatus binds

Pyrimidine base in DNA and RNA

Loss of an amino group (NH2) from a base

Refers to the fact that the genetic code contains more information than is needed to specify all 20 common amino acids

Mutation in which one or more nucleotides are deleted from a DNA sequence

Long terminal repeat in Ty elements of yeast

Process that separates the strands of double-stranded DNA when DNA is heated

Basic building block of DNA, consisting of deoxyribose, a phosphate, and a nitrogenous base

Five-carbon sugar in DNA; lacks a hydroxyl group on the 2'-carbon atom

Break in the covalent bond connecting a purine base to the 1'-carbon atom of deoxyribose, resulting in the loss of the purine base. The resulting apurinic site cannot provide a template in replication, and a nucleotide with another base may be incorporated into the newly synthesized DNA strand opposite the apurinic site

DNA repair in which modified bases are changed back into their original structures

Replication of the lagging strand in the direction opposite that of unwinding, which means that DNA must be synthesized in short stretches (Okazaki fragments)

DNA dependent DNA polymerase

DNA dependent RNA polymerase

E. coli topoisomerase enzyme that relieves the torsional strain that builds up ahead of the replication fork

Protein that unwinds double-stranded DNA by breaking hydrogen bonds

Enzyme that catalyzes the formation of a phosphodiester bond between adjacent 3'-OH and 5'-phosphate groups in a DNA molecule

Modification of DNA by the addition of methyl groups to certain positions on the bases

Enzyme that synthesizes DNA

Bacterial DNA polymerase that removes and replaces RNA primers with DNA nucleotides

Bacterial DNA polymerase that takes part in DNA repair; Restarts replication after synthesis has halted because of DNA damage

Bacterial DNA polymerase that synthesizes new nucleotide strands off the primers

DNA sequence capable of moving from one site to another within the genome through a mechanism that differs from that of homologous recombination

dNTP

Protein that regenerates elongation factor Tu in the elongation stage of protein synthesis

Protein that combines with GTP and is required for movement of the ribosome along the mRNA during translation

Protein taking part in the elongation stage of protein synthesis; forms a complex with GTP and a charged amino acid and then delivers the charged tRNA to the ribosome

Endosymbiosis

Sequence that stimulates maximal transcription of distant genes; affects only genes on the same DNA molecule (is cis acting), contains short consensus sequences, is not fixed in relation to the transcription start site, can stimulate almost any promoter in its vicinity, and may be upstream or downstream of the gene. The function is independent of sequence orientation

Method used to separate molecules or organelles of different density by centrifugation

Error correcting (Error checking)

Chromatin that undergoes condensation and decondensation in the course of the cell cycle

One of 3 sites in a ribosome occupied by a tRNA. In the elongation of translation, tRNA moves from the peptidyl (P) site to the E site from which it then exits the ribosome

Coding region of a split gene (a gene that is interrupted by introns). After processing, the __ remain in the messenger RNA

Mutation in which the number of copies of a trinucleotide (or some multiple of 3 nucleotides) increases in succeeding generations

Facultative Heterochromatin

Short, directly repeated sequence produced on either side of a transposable element when the element inserts into DNA

Alters a wild-type phenotype

Alters the reading frame of a gene

Produces a new trait or causes a trait to appear in inappropriate tissues or at inappropriate times in development

Process of nonreciprocal genetic exchange that can produce abnormal ratios of gametes following meiosis

Set of genes similar in sequence that arose through repeated duplication events; often encode different proteins

Affects a single gene or locus

Protein that binds to eukaryotic promoters near the start site and is a part of the basal transcription apparatus that initiates transcription

Mutation in a germ-line cell (one that gives rise to gametes)

Belongs to a class of introns in some ribosomal RNA genes that are capable of self-splicing

Belongs to a class of introns in some protein-encoding genes that are capable of self-splicing and are found in mitochondria, chloroplasts, and a few eubacteria

Purine base in DNA and RNA

RNA molecule that serves as a template for an alteration made in mRNA during RNA editing

Secondary structure formed when sequences of nucleotides on the same strand are complementary and pair with each other

Chromatin that remains in a highly condensed state throughout the cell cycle; Found at the centromeres and telomeres of most chromosomes

DNA consisting of 2 strands, each of which is from a different chromosome

DNA that consists of short sequences that are present in hundreds of thousands to millions of copies; clustered in certain regions of chromosomes

Low-molecular-weight protein found in eukaryotes that complexes w/ DNA to form chromosomes

Model of homologous recombination that is initiated by single-strand breaks in a DNA molecule

Complex of an enzyme and other protein factors necessary for complete function

Exchange of genetic information between homologous DNA molecules

Sudden appearance of numerous mutations, chromosome aberrations, and sterility in the offspring of a cross between a male fly that possesses P elements and a female fly that lacks them

Pairing of two partly or fully complementary single-stranded nucleotide chains

Deletion of some multiple of three nucleotides, which does not alter the reading frame of the gene

Insertion of some multiple of three nucleotides, which does not alter the reading frame of the gene

Incorporation of a damaged nucleotide or mismatched base pair into a DNA molecule

Results from environmental agents, such as chemicals or radiation

The codon in mRNA that specifies the first amino acid (fMet in bacterial cells; Met in eukaryotic cells) of a protein; most commonly AUG

Protein required for the initiation of translation in bacterial cells; Enhances the dissociation of the large and small subunits of the ribosome

Protein required for the initiation of translation in bacterial cells; Forms a complex with GTP and the charged initiator protein and then delivers the charged tRNA to the initiation complex

Protein required for the initiation of translation in bacterial cells; Binds to the small subunit of the ribosome and prevents the large subunit from binding during initiation

Binds to an origin of replication and unwinds a short stretch of DNA, allowing helicase and other single-stranded binding proteins to bind and initiate replicaiton

Mutation in which nucleotides are added to a DNA sequence

Simple type of transposable element found in bacteria and their plasmids that contains only the information necessary for its own movement

Chemical substance that is about the same size as a nucleotide and may become sandwiched between adjacent bases in DNA, distorting the 3D structure of the helix and causing single-nucleotide insertions and deletions in replication

Occurs in a gene (locus) that is different from the gene containing the original mutation

Located w/in the sequences of DNA that are transcribed into RNA

Interspersed elements

Repeated sequence at multiple locations throughout the genome

Occurs in the same gene (locus) as the mutation that it suppresses

Intervening sequence in a split gene; Removed from the RNA after transcription

Different tRNAs w/ different anticodons that specify the same amino acid

Different forms of an element that have the same number of protons and electrons but differ in the number of neutrons in the nucleus

L1

DNA strand that is replicated discontinuously

The larger of the 2 subunits of a functional ribosome

Looplike structure created in the splicing of nuclear pre-mRNA in which the 5' end of an intron is attached to a branch point in pre-mRNA

DNA strand that is replicated continuously

Causes premature death

Stretch of DNA separating two nucleosomes

Long DNA sequence repeated many times and interspersed throughout the genome

Causes the complete or partial absence of normal function

Matrix attachment regions

Midpoint of the melting range of DNA

RNA molecule that carries genetic information for the amino acid sequence of a protein

Small RNAs, typically 21 or 22 bp in length, that are produced by cleavage of double-stranded RNA arising from small hairpins w/in RNA that is mostly single stranded. The __ combine w/ proteins to form a complex that binds (imperfectly) to mRNA molecules and inhibits their translation

Process that corrects mismatched nucleotides in DNA after replication has been completed. Enzymes excise incorrectly paired nucleotides from the newly synthesized strand and use the original nucleotide strand as a template when replacing them

Alters a codon in the mRNA, resulting in a different amino acid in the protein encoded

Mitochondrial Eve

DNA consisting of sequences that are from 150 to 300 bp in length and are repeated thousands of times

Rare base found in some RNA molecules. Such bases are modified forms of the standard bases (adenine, guanine, cytosine, and uracil)

Molecule that assists in the proper folding of another molecule

Mechanisms for the detection and elimination of mRNAs that contain errors that may create problems in the course of translation

Refers to the presence of more than one 3' cleavage site on a single pre-mRNA, which allows cleavage and polyadenylation to take place at different sites, producing mRNAs of different lengths

Any environmental agent that significantly increases the rate of mutation above the spontaneous rate

Heritable change in genetic information

Frequency w/ which a gene changes from the wild type to a specific mutant; Generally expressed as the number of mutations per biological unit (that is, mutations per cell division, per gamete, or per round of replication

Coiled tertiary structure that forms when strain is placed on a DNA helix by underwinding of the helix

Changes the amino acid sequence of a protein but does not alter the function of the protein

Nitrogen-containing base that is one of the three parts of a nucleotide

One of a heterogeneous assortment of nonhistone proteins in chromatin

Refers to the fact that, generally, each nucleotide is a part of only one codon and encodes only one amino acid in a protein

Type of transposition in which a transposable element excises from an old site and moves to a new site, resulting in no net increase in the number of copies of the transposable element

Changes in a sense codon (one that specifies an amino acid) in to a stop codon

Process that brings about the rapid elimination of mRNA that has a premature stop codon

Mechanism in eukaryotic cells for dealing w/ ribosomes stalled at the 3' end of an mRNA that lacks a termination codon. A protein binds to the A site of the stalled ribosome and recruits other proteins that degrade the mRNA from the 3' end

The DNA strand that is complementary to the template strand; not ordinarily used as a template during transcription

Belongs to a class of introns in protein-encoding genes that reside in the nuclei of eukaryotic cells; removed by spliceosomeal-mediated splicing

Bacterial DNA confined to a definite region of the cytoplasm

Ribose or deoxyribose bonded to a base

Basic repeating unit of chromatin, consisting of a core of eight histone proteins (two of each of H2A, H2B, H3 and H4) and about 146 bp of DNA that wraps around the core about two times

Repeating unit of DNA and RNA made up of a sugar, a phosphate, and a base

DNA repair that removes bulky DNA lesions and other types of DNA damage

Short stretch of newly synthesized DNA. Produced by discontinuous replication on the lagging strand, these fragments are eventually joined together

Idea proposed by Beadle and Tatum that each gene encodes a separate enzyme

Modification of the one gene, one enzyme hypothesis; Proposes that each gene encodes a separate polypeptide chain

Ori

OriH

OriL

Chemical bond that connects amino acids in a protein

One of three sites in a ribosome occupied by a tRNA in translation. In the elongation stage of protein synthesis, tRNAs move from the aminoacyl (A) site into the __

A phosphorous atom attached to four oxygen atoms; one of three components of a nucleotide

Phosphodiester bond connecting two nucleotides in a polynucleotide strand

Small RNA molecule belonging to a class named after Piwi proteins w/ which these molecules interact; Similar to microRNAs and small interfering RNAs and thought to have a role in the regulation of sperm development

String of adenine nucleotides added to the 3' end of a eukaryotic mRNA after transcription

Single bacterial RNA molecule that encodes more than one polypeptide chain; uncommon in eukaryotes

Series of nucleotides linked together by phosphodiester bonds

Chain of amino acids linked by peptide bonds; Also called a protein

Messenger RNA molecule with several ribosomes attached to it

Giant chromosome in the salivary glands of Drosophila melanogaster. Each polytene chromosome consists of a number of DNA molecules lying side by side

Coiled tertiary structure that forms when strain is placed on a DNA helix by overwinding of the helix

Eukaryotic RNA molecule that is modified after transcription to become mRNA

Enzyme that synthesizes a short stretch of RNA on a DNA template; Functions in replication to provide a 3'-OH group for the attachment of a DNA molecule

Short stretch of RNA on a DNA template; Provides a 3'-OH group for the attachment of a DNA nucleotide at the initiation of replication

DNA sequence to which the transcription apparatus binds so as to initiate transcription; Indicates the direction of transcription, which of the 2 DNA strands is to be read as the template, and the starting point of transcription

Ability of DNA polymerases to remove and replace incorrectly paired nucleotides in the course of replication

The part of mRNA consisting of the nucleotides that specify the amino acid sequence of a protein

Type of nitrogenous base in DNA and RNA. Adenine and guanine are __

Type of nitrogenous base in DNA and RNA. Cytosine, thymine, and uracil are __

Structure in which a bond forms between two adjacent pyrimidine molecules on the same strand of DNA; Disrupts normal hydrogen bonding between complementary bases and distorts the normal configuration of the DNA molecule

Particular way in which a nucleotide sequence is read in groups of 3 nucleotides (codons) in translation. Each __ begins with a start codon and ends w/ a stop codon

DNA sequence located immediately upstream of the core promoter that affects transcription; Contains consensus sequences to which transcriptional activator proteins bind

Energy state of a DNA molecule when there is no structural strain on the molecule

Protein required for the termination of transcription; Binds to a ribosome when a stop codon is reached and stimulates the release of the polypeptide chain, the tRNA, and the mRNA from the ribosome

The process by which two complementary single-stranded DNA molecules pair

Sequences that exist in multiple copies in a genome

Process by which DNA is synthesized from a single-stranded nucleotide template

Segment of DNA molecule that is unwinding and undergoing replication

Replication of an incorporated error in which a change in the DNA sequence has been replicated and all base pairings in the new DNA molecule are correct

Point at which a double-stranded DNA molecule separates into two single strands that serve as templates for replication

Protein that ensures that replication takes place only once at each origin; Required at the origin before replication can be initiated and removed after the DNA has been replicated

Sequence of nucleotides where replication is initiated

Type of transposition in which a copy of the transposable element moves to a new site while the original copy remains at the old site; Increases the number of copies of the transposable element

Replicative transposon

Unit of replication, consisting of DNA from the origin of replication to the point at which replication on either side of the origin ends

Enzyme required for some types of transposition; Brings about resolution- that is, crossing over between sites located w/in the transposable element. __ may be encoded by the transposable element or by a cellular enzyme that normally functions in homologous recombination

Type of transposable element in eukaryotic cells that possesses some characteristics of retroviruses and transposes through an RNA intermediate

Mutation that changes a mutant phenotype back into the wild type

Synthesis of DNA from an RNA template

Subunit of bacterial RNA polymerase that facilitates the termination of transcription of some genees

Sequence in bacterial DNA that requires the presence of the rho subunit of RNA polymerase to terminate transcription

Sequence in bacterial DNA that does not require the presence of the rho subunit of RNA polymerase to terminate transcription

Substrate of RNA synthesis; Consists of ribose, a nitrogenous base, and 3 phosphates linked to the 5'-carbon atom of the ribose. In transcription, 2 of the phosphates are cleaved, producing an RNA nucleotide

Nucleotide containing ribose; present in RNA

5 carbon sugar in RNA

RNA molecule that is a structural component of the ribosome

RNA molecule that can act as a biological catalyst

RNA dependent DNA polymerase

RNA dependent RNA polymerase

Process in which the protein-coding sequence of an mRNA is altered after transcription. The amino acids specified by the altered mRNA are different from those predicted from the nucleotide sequence of the gene encoding the protein

Process in which cleavage of double-stranded RNA produces small interfering RNAs (siRNAs) that bind to mRNAs containing complementary sequences and bring about their cleavage and degradation

Enzyme that synthesizes RNA from a DNA template during transcription

Eukaryotic RNA polymerase that transcribes large ribosomal RNA molecules (18 S rRNA and 28 S rRNA)

Eukaryotic RNA polymerase that transcribes pre-messenger RNA, some small nuclear RNAs, and some microRNAs

Eukaryotic RNA polymerase that transcribes transfer RNA, small ribosomal RNAs (5 S rRNA), some small nuclear RNAs, and some microRNAs

Transcribes small interfering RNAs in plants

Process in some viruses by which RNA is synthesized from an RNA template

Process by which introns are removed and exons are joined together

Sequence of DNA nucleotides that encodes an RNA molecule

Combination of a small interfering RNA (siRNA) molecule or a microRNA (miRNA) molecule and proteins that can cleave mRNA, leading to the degradation of the mRNA, or affect transcription or repress translation of the mRNA

Replication of circular DNA that is initiated by a break in one of the nucleotide strands, producing a double-stranded circular DNA molecule and a single-stranded linear DNA molecule, the latter of which may circularize and serve as a template for the synthesis of a complementary strand

Replication in which the two nucleotide strands of DNA separate, each serving as a template for the synthesis of a new strand. All DNA replication is __

Codon that specifies an amino acid in a protein

Consensus sequence found in the bacterial 5' untranslated region of mRNA; Contains the ribosome-binding site

Short DNA sequence repeated many times and interspersed throughout the genome

Subunit of bacterial RNA polymerase that allows the RNA polymerase to recognize a promoter and initiate transcription

From 15 to 30 amino acids that are found at the amino end of some eukaryotic proteins and direct the protein to specific locations in the cell; Usually cleaved from the protein

Change in the nucleotide sequence of DNA that does not alter the amino acid sequence of a protein

Binds to single-stranded DNA in replication and prevents it from annealing w/ a complementary strand and forming secondary structures

Small RNA molecule found in the cytoplasm of eukaryotic cells

Single-stranded RNA molecule (usually from 21-25 nucleotides in length) produced by the cleavage and processing of double-stranded RNA; Binds to complementary sequences in mRNA and brings about the cleavage and degradation of the mRNA. Some __ bind to complementary sequences in DNA and bring about their methylation

Structure found in the nuclei of eukaryotic cells that consists of small nuclear RNA (snRNA) and proteins; Functions in the processing of pre-mRNA

Small RNA molecule found in the nuclei of eukaryotic cells; Functions in the processing

Small RNA molecule found in the nuclei of eukaryotic cells; Function in the processing of rRNA and in the assembly of ribosomes

The smaller of the two subunits of a functional ribosome

Mutation in a cell that does not give rise to a gamete

System of proteins and enzymes that allow a cell to replicate its DNA in the presence of a distortion in DNA structure; Makes numerous mistakes in replication and increases the rate of mutation

Large complex consisting of several RNAs and many proteins that splices protein-encdoding pre-mRNA; Contains 5 small ribonucleoprotein particles (U1, U2, U4, U5, and U6)

Arises spontaneously from natural changes in DNA structure or from errors in replication

Codon in mRNA that signals the end of translation. The 3 common __ are UAA, UAG, and UGA

Slipping of the template and newly synthesized strands in replication in which one of the strands loops out from the other and nucleotides are inserted or delete on the newly synthesized strand

Coiled tertiary structure that forms when strain is placed on a DNA helix by overwinding or underwinding of the helix

Hides or suppresses the effect of another mutation at a site that is distinct from the site of the original mutation

Different codons that specify the same amino acid

DNA sequences repeated one after another; tend to be clustered at specific locations on a chromosome

Consensus sequence (TATAAAA) commonly found in eukaryotic RNA polymerase II promoters; Usually located from 25-30 bp upstream of the transcription start site. The __ determines the start point for transcription

Polypeptide chain found in several different transcription factors that recognizes and binds to sequences in eukaryotic promoters

Enzyme that is made up of both protein and RNA and replicates the ends (telomeres) of eukaryotic chromosomes. The RNA part of the enzyme has a template that is complementary to repeated sequences in the telomere and pairs w/ them, providing a template for the synthesis in the telomere and pairs w/ them, providing a template for the synthesis of additional copies of the repeats

Sequence found at the end of a chromosome next to the telomeric sequence; Consists of relatively long, complex repeated sequences

Sequence found at the ends of a chromosome; Consists of many copes of short, simple sequences repeated one after the other

The strand of DNA that is used as a template during transcription. The RNA synthesized during transcription is complementary and antiparallel to the __

Sequences found at both ends of a transposable element that are inverted complements of one another

Sequence of DNA nucleotides that causes the termination of transcription

Replication of circular DNA that is initiated by the unwinding of the 2 nucleotide strands, producing a replication bubble. Unwinding continues at one or both ends of the bubble, making it progressively larger. DNA replication on both of the template strands is simultaneous w/ unwinding until the 2 replication forks meet

Pyrimidine base in DNA but not in RNA

Enzyme that adds or removes rotations in a DNA helix by temporarily breaking nucleotide strands; Controls the degree of DNA supercoiling

Trans-acting factor

The process of splicing together exons from two or more pre-mRNAs

Process by which RNA is synthesized from a DNA template

Sequence of nucleotides in DNA that encodes a single RNA molecule, along w/ the sequences necessary for its transcription; Normally contains a promoter, an RNA-coding sequence, and a terminator

Protein in eukaryotic cells that binds to consensus sequences in regulatory promoters or enhancers and affects transcription initiation by stimulating or inhibiting the assembly of the basal transcription apparatus

RNA molecule that carries an amino acid to the ribosome and transfers it to a growing polypeptide chain in translation

Belongs to a class of introns in tRNA genes. The splicing of these genes relies on enzymes

An RNA molecule that has properties of both mRNA and tRNA; Functions in rescuing ribosomes that are stalled at the end of mRNA

Substance responsible for transformation. DNA is the transforming principle

Base substitution in which a purine is replaced by a different purine or pyrimidine is replaced by a different pyrimidine

Process by which a protein is assembled from information contained in the messenger RNA

Movement of a chromosome segment to a nonhomologous chromosome or to a region w/in the same chromosome. Also, movement of a ribosome along mRNA in the course of translation

DNA sequence capable of moving from one site to another w/in the genome through a mechanism that differs from that of homologous recombination

Enzyme encoded by many types of transposable elements that is required for their transposition. The enzyme makes single-strand breaks at each end of the transposable element an on either side of the target sequence where the element inserts

Movement of a transposable genetic element from one site to another. Replicative __ increases the number of copies of the transposable element; Nonreplicative __ does not increase the number of copies

Base substitution in which a purine is replaced by a pyrimidine or a pyrimidine is replaced by a purine

Triphosphates

Chemical reaction in which an aminoacyl-tRNA synthetase attaches an amino acid to its corresponding tRNA

Creates a modified base in RNA by catalyzing a chemical change in the standard base

Misalignment of the two DNA molecules during crossing over, resulting in one DNA molecule w/ an insertion and the other w/ a deletion

Sequence present only once or a few times in a genome

Refers to the fact that particular codons specify the same amino acids in almost all organisms

Consensus sequence found in some bacterial promoters that contains a number of A-T pairs and is found about 40 to 60 bp upstream of the transcription start site

Pyrimidine base in RNA but not normally in DNA

Base pairing between codon and anticodon in which there is nonstandard pairing, usually at the third (3') position of the codon; Allows more than one codon to pair w/ same anticodon

Method for analyzing the 3D shape and structure of chemical substances. Crystals of a substance are bombarded w/ X-rays, which hit the crystals, bounce off, and produce a diffraction pattern on a detector. The pattern of the spots produced on the detector provides info about the molecular structure

Secondary structure of DNA characterized by a gene or genes on the Y chromosome