Topic 7.1
Base sequencing
the procedure of determining the order of nucleotides in a DNA section.
Topic 7.1
DNA gyrase
a bacterial enzyme that catalyses the breaking and re-joining of bonds linking adjacent nucleotides in circular DNA to generate supercoiled DNA helices.
Topic 7.1
DNA polymerases
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.
Topic 7.1
DNA primase
an enzyme involved in the initiation of DNA replication that catalyses the polymerization of short RNA primers on the template DNA.
Topic 7.1
DNA profiling
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.
Topic 7.1
DNA replication
the process of making an identical copy of a DNA molecule, using existing DNA as a template for the synthesis of new DNA strands.
Topic 7.1
Helicase
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.
Topic 7.1
Histone
any of several small, basic proteins most commonly found in association with the DNA in the chromatin of eukaryotes.
Topic 7.1
Intron
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.
Topic 7.1
Lagging strand
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.
Topic 7.1
Leading strand
DNA strand being replicated by continuous polymerization at the 3 growing tip.
Topic 7.1
Nucleosome
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.
Topic 7.1
Nucleotides
the building blocks of a nucleic acid, consisting of a carbon sugar covalently bonded to a nitrogenous base and a phosphate group.
Topic 7.1
Primer
a segment of DNA or RNA that is complementary to a given DNA sequence and that is needed to initiate replication by DNA polymerase.
Topic 7.1
Replication fork
a site on a DNA molecule at which the unwinding of the helices and synthesis of daughter molecules are both occurring during DNA replication.
Topic 7.1
Tandem repeats
copies of genes repeated one afer another along a chromosome.
Topic 7.1
Telomere
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.
Topic 7.1
X-ray diffraction
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.
Topic 7.2
5' to 3' direction
the only direction that DNA polymerase can synthesize DNA; it does so by adding nucleotides to the 3' end of a DNA strand.
Topic 7.2
DNA methylation
the modification of a strand of DNA afer it is replicated, in which a methyl (CH3) group is added and is one of the methods used to regulate the expression of genes.
Topic 7.2
Exon
sequence of DNA that codes information for protein synthesis that is transcribed to messenger RNA.
Topic 7.2
Gene expression
conversion of the information from the gene into mRNA via transcription and then to protein via translation resulting in the phenotypic manifestation of the gene.
Topic 7.2
Genome
total genetic contents of an organism.
Topic 7.2
Intron
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.
Topic 7.2
Non-coding DNA components
of an organism's DNA that do not encode protein sequences. Some non-coding DNA is transcribed into functional non-coding RNA molecules while others are not transcribed.
Topic 7.2
Nucleosome
structural unit of a eukaryotic chromosome, consisting of a length of DNA coiled around a core of histones.
Topic 7.2
Promoter
site in a DNA molecule at which RNA polymerase and transcription factors bind to initiate transcription of mRNA.
Topic 7.2
Repressor
substance that binds to the operator and obstructs the RNA polymerase from binding to the promoter and transcribing the gene.
Topic 7.2
Splicing of mRNA
removal of introns from a primary transcript and the subsequent joining of exons in the production of a mature RNA molecule.
Topic 7.2
Terminator
sequence of nucleotides that signals the end of transcription or translation and the completion of the synthesis of a nucleic acid or protein molecule.
Topic 7.2
Transcription
process by which messenger RNA is synthesized from a DNA template resulting in the transfer of genetic information from the DNA molecule to the messenger RNA.
Topic 7.3
Alpha helix
a coiled conformation common in many proteins; it is characterized by a spiral chain of amino acids stabilized by hydrogen bonds in which the resulting structure resembles a spring or helix.
Topic 7.3
Beta pleated sheet
a structure that occurs in many proteins and consists of two or more parallel adjacent polypeptide chains arranged in a zigzag pattern, so that hydrogen bonds can form between the chains.
Topic 7.3
Bound ribosomes
ribosomes that are attached to the outer surfaces of endoplasmic reticulum and produce proteins that are used within the plasma membrane or are expelled from the cell via exocytosis.
Topic 7.3
Conjugated protein
a biochemical compound, such as hemoglobin, made up of a protein molecule and a non-protein prosthetic group.
Topic 7.3
Different conformations
Alternative structures of the same protein.
Topic 7.3
Electron micrograph
a photograph or image of a specimen taken using an electron microscope.
Topic 7.3
Free ribosomes
can move about anywhere in the cytoplasm and the proteins they make are free to go anywhere within the cell.
Topic 7.3
Non-polar amino acid
an alpha-amino acid in which the functional group (R-) attached to the alpha-carbon has hydrophobic properties.
Topic 7.3
Polar amino acid
an alpha-amino acid in which the functional group (R-) attached to the alpha-carbon has hydrophilic properties.
Topic 7.3
Polypeptide
A polymer of amino acids joined together by peptide bonds.
Topic 7.3
Polysome
a group of ribosomes joined by a molecule of messenger RNA containing the genetic information code that is to be translated during protein synthesis.
Topic 7.3
Primary structure
the linear sequence or order of amino acids of a protein; it determines how the protein will fold into a more advanced structure, such as the unique three-dimensional structure of protein.
Topic 7.3
Prosthetic group
the non-protein component of a conjugated protein, for example the heme group in hemoglobin.
Topic 7.3
R group
the chemical group attached to the alpha carbon in an amino acid that is different for each of the common 20 amino acids found in proteins.
Topic 7.3
Quaternary structure
the particular shape of a protein defined by the characteristic three-dimensional arrangement of its constituent polypeptide subunits.
Topic 7.3
Secondary structure
the repetitive folding of the polypeptide backbone of a protein due to the hydrogen bonds formed between the peptides.
Topic 7.3
Tertiary structure
the irregular folding of a protein molecule due to the interactions of the R- groups involving hydrophobic interactions, ionic bonds, hydrogen bonds, or disulfide bonds.
Topic 7.3
Translation
the transfer of information from a RNA molecule into a polypeptide, involving the changing of language from nucleic acid to amino acid.
Topic 7.3
tRNA
RNA molecules that transport amino acids to ribosomes for incorporation into a polypeptide undergoing synthesis (according to directions coded in the mRNA).
Topic 7.1
Base sequencing
the procedure of determining the order of nucleotides in a DNA section.
Topic 7.1
DNA gyrase
a bacterial enzyme that catalyses the breaking and re-joining of bonds linking adjacent nucleotides in circular DNA to generate supercoiled DNA helices.
Topic 7.1
DNA polymerases
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.
Topic 7.1
DNA primase
an enzyme involved in the initiation of DNA replication that catalyses the polymerization of short RNA primers on the template DNA.
Topic 7.1
DNA profiling
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.
Topic 7.1
DNA replication
the process of making an identical copy of a DNA molecule, using existing DNA as a template for the synthesis of new DNA strands.
Topic 7.1
Helicase
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.
Topic 7.1
Histone
any of several small, basic proteins most commonly found in association with the DNA in the chromatin of eukaryotes.
Topic 7.1
Intron
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.
Topic 7.1
Lagging strand
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.
Topic 7.1
Leading strand
DNA strand being replicated by continuous polymerization at the 3 growing tip.
Topic 7.1
Nucleosome
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.
Topic 7.1
Nucleotides
the building blocks of a nucleic acid, consisting of a carbon sugar covalently bonded to a nitrogenous base and a phosphate group.
Topic 7.1
Primer
a segment of DNA or RNA that is complementary to a given DNA sequence and that is needed to initiate replication by DNA polymerase.
Topic 7.1
Replication fork
a site on a DNA molecule at which the unwinding of the helices and synthesis of daughter molecules are both occurring during DNA replication.
Topic 7.1
Tandem repeats
copies of genes repeated one afer another along a chromosome.
Topic 7.1
Telomere
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.
Topic 7.1
X-ray diffraction
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.
Topic 7.2
5' to 3' direction
the only direction that DNA polymerase can synthesize DNA; it does so by adding nucleotides to the 3' end of a DNA strand.
Topic 7.2
DNA methylation
the modification of a strand of DNA afer it is replicated, in which a methyl (CH3) group is added and is one of the methods used to regulate the expression of genes.
Topic 7.2
Exon
sequence of DNA that codes information for protein synthesis that is transcribed to messenger RNA.
Topic 7.2
Gene expression
conversion of the information from the gene into mRNA via transcription and then to protein via translation resulting in the phenotypic manifestation of the gene.
Topic 7.2
Genome
total genetic contents of an organism.
Topic 7.2
Intron
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.
Topic 7.2
Non-coding DNA components
of an organism's DNA that do not encode protein sequences. Some non-coding DNA is transcribed into functional non-coding RNA molecules while others are not transcribed.
Topic 7.2
Nucleosome
structural unit of a eukaryotic chromosome, consisting of a length of DNA coiled around a core of histones.
Topic 7.2
Promoter
site in a DNA molecule at which RNA polymerase and transcription factors bind to initiate transcription of mRNA.
Topic 7.2
Repressor
substance that binds to the operator and obstructs the RNA polymerase from binding to the promoter and transcribing the gene.
Topic 7.2
Splicing of mRNA
removal of introns from a primary transcript and the subsequent joining of exons in the production of a mature RNA molecule.
Topic 7.2
Terminator
sequence of nucleotides that signals the end of transcription or translation and the completion of the synthesis of a nucleic acid or protein molecule.
Topic 7.2
Transcription
process by which messenger RNA is synthesized from a DNA template resulting in the transfer of genetic information from the DNA molecule to the messenger RNA.
Topic 7.3
Alpha helix
a coiled conformation common in many proteins; it is characterized by a spiral chain of amino acids stabilized by hydrogen bonds in which the resulting structure resembles a spring or helix.
Topic 7.3
Beta pleated sheet
a structure that occurs in many proteins and consists of two or more parallel adjacent polypeptide chains arranged in a zigzag pattern, so that hydrogen bonds can form between the chains.
Topic 7.3
Bound ribosomes
ribosomes that are attached to the outer surfaces of endoplasmic reticulum and produce proteins that are used within the plasma membrane or are expelled from the cell via exocytosis.
Topic 7.3
Conjugated protein
a biochemical compound, such as hemoglobin, made up of a protein molecule and a non-protein prosthetic group.
Topic 7.3
Different conformations
Alternative structures of the same protein.
Topic 7.3
Electron micrograph
a photograph or image of a specimen taken using an electron microscope.
Topic 7.3
Free ribosomes
can move about anywhere in the cytoplasm and the proteins they make are free to go anywhere within the cell.
Topic 7.3
Non-polar amino acid
an alpha-amino acid in which the functional group (R-) attached to the alpha-carbon has hydrophobic properties.
Topic 7.3
Polar amino acid
an alpha-amino acid in which the functional group (R-) attached to the alpha-carbon has hydrophilic properties.
Topic 7.3
Polypeptide
A polymer of amino acids joined together by peptide bonds.
Topic 7.3
Polysome
a group of ribosomes joined by a molecule of messenger RNA containing the genetic information code that is to be translated during protein synthesis.
Topic 7.3
Primary structure
the linear sequence or order of amino acids of a protein; it determines how the protein will fold into a more advanced structure, such as the unique three-dimensional structure of protein.
Topic 7.3
Prosthetic group
the non-protein component of a conjugated protein, for example the heme group in hemoglobin.
Topic 7.3
R group
the chemical group attached to the alpha carbon in an amino acid that is different for each of the common 20 amino acids found in proteins.
Topic 7.3
Quaternary structure
the particular shape of a protein defined by the characteristic three-dimensional arrangement of its constituent polypeptide subunits.
Topic 7.3
Secondary structure
the repetitive folding of the polypeptide backbone of a protein due to the hydrogen bonds formed between the peptides.
Topic 7.3
Tertiary structure
the irregular folding of a protein molecule due to the interactions of the R- groups involving hydrophobic interactions, ionic bonds, hydrogen bonds, or disulfide bonds.
Topic 7.3
Translation
the transfer of information from a RNA molecule into a polypeptide, involving the changing of language from nucleic acid to amino acid.
Topic 7.3
tRNA
RNA molecules that transport amino acids to ribosomes for incorporation into a polypeptide undergoing synthesis (according to directions coded in the mRNA).