Chapter 20 Biotechnology
nucleic acid probe
nucleic-acid fragment that is complementary to another nucleic-acid sequence and thus, when labeled in some manner, as with a radioisotope, can be used to identify complementary segments present in the nucleic acid sequences
) Bacteria that do not take up any plasmids would grow on which media?
nutrient broth
recombinant DNA
or rDNA, is the term used to describe the combination of two DNA strands that are constructed artificially
genetic engineering
the modification of an organism's genetic composition by artificial means, often involving the transfer of specific traits, or genes, from one organism into a plant or animal of an entirely different species.
major differences between the two
The cDNA clone will only contain the sequences found in the mRNA, not the entire gene while the genomic clone could have the sequences of the entire gene. 2) A cDNA library will not contain a clone of every gene of the organism.
Probes are short, single-stranded DNA or RNA segments that are used to identify DNA fragments with a particular sequence. In order to identify a specific restriction fragment using a probe, what must be done
The fragments must be separated by electrophoresis. The fragments must be treated with heat or chemicals to separate the strands of the double helix. The probe must be hybridized with the fragment
vector
transmits *transfer* a disease or parasite from one animal or plant to another.
southern blotting
used for detection of a specific DNA sequence in DNA samples. Southern blotting combines transfer of electrophoresis-separated DNA fragments to a filter membrane and subsequent fragment detection by probe hybridization
gel electrophoresis
a method for separation and analysis of macromolecules and fragments based on size/charge
Plasmids are important in biotechnology because they are
a vehicle for the insertion of foreign genes into bacteria
nutrient broth
used for the general cultivation of a wide variety of microorganisms. A liquid medium, it is produced according to the formula from APHA and AOAC, and supports the growth of a great variety of microorganisms that are not very nutritionally demanding.
electron microscopy
uses a beam of electrons to create an image of the specimen. It is capable of much higher magnifications and has a greater resolving power than a light microscope
genomic library
contains DNA fragments that represent the entire genome of an organism
Characteristics of cloning vectors
1. Origin of replication 2. marker genes for selection and/or screening selection - killing cells that lack specific gene - e.g. antibiotic resistance genes 3. Unique restriction endonuclease (RE) sites. - allow inserts to be cloned in specific sites on plasmid 4. transmissability. many wild type plasmids are transmissable by conjugation 5. Promoters for gene expression
cDNA library
mRNA from an organism or from an organism or from specific cells of an organism are extracted and then complementary DNA (cDNAs) are prepared from the mRNA in a multistep reaction catalysed by the enzyme reverse transcriptase
) The polymerase chain reaction is important because it allows us to
make many copies of a targeted segment of DNA
What is the most logical sequence of steps for splicing foreign DNA into a plasmid and inserting the plasmid into a bacterium? I. Transform bacteria with recombinant DNA molecule. II. Cut the plasmid DNA using restriction enzymes. III. Extract plasmid DNA from bacterial cells. IV. Hydrogen-bond the plasmid DNA to nonplasmid DNA fragments. V. Use ligase to seal plasmid DNA to nonplasmid DNA.
III, II, IV, V, I
sticky ends
Longer overhangs of DNA
A paleontologist has recovered a bit of tissue from the 400-year-old preserved skin of an extinct dodo (a bird). The researcher would like to compare DNA from the sample with DNA from living birds. Which of the following would be most useful for increasing the amount of dodo DNA available for testing?
PCR
RNA interface
RNA molecules inhibit gene expression, typically by causing the destruction of specific mRNA molecules
RFLP analysis
Restriction fragment length polymorphism or RFLP analysis is used to identify a change in the genetic sequence that occurs at a site where a restriction enzyme cuts. RFLPs can be used to trace inhertitance patterns, identify specific mutations, and for other molecular genetic techniques.
which of the following (in the double stranded form) will be a restriction site where a restriction endonuclease can cut?
TTATAA
enzymatic function of restriction enzyme
cleave nucleic acids at specific sites
restriction fragment ligation
joining of two restriction enzyme fragments
Which of the following would not be true of cDNA produced using mouse brain tissue as the starting material?
A) It could be amplified by the polymerase chain reaction. * B) It could be used to create a complete genomic library.* C) It is produced from mRNA using reverse transcriptase. D) It could be used as a probe to locate genes expressed in the brain. E) It lacks the introns of the human genes and thus can probably be introduced into phage vectors.
Which of these is not one of the procedures used in Southern blotting?
A) electrophoresis B) hybridization C) autoradiography D) restriction fragment preparation *E) DNA microarray assay (is not)*
In order to insert a human gene into a plasmid, both must
be cut by the same restriction enzyme or two enzymes that produce the same sticky ends.
electroportation
electrical field is applied to cells in order to increase the permeability of the cell membrane, allowing chemicals, drugs, or DNA to be introduced into the cell.
A eukaryotic protein can be made in bacteria by inserting the gene encoding the protein into a(n)
expression vector.
Genomics includes the study of
identifying the location of all of the genes present in the genome. B) comparing genomes between different organisms. C) studying the coordinated expression of groups of genes under various conditions or in different cell types. identifying the functions of all of the genes in the genome
autoradiography
image on an x-ray film or nuclear emulsion produced by the pattern of decay emissions (e.g., beta particles or gamma rays) from a distribution of a radioactive substance.
where can restriction endonuclease cut?
palindromic sequence is a nucleic acid sequence on double-stranded DNA or RNA wherein reading 5' (five-prime) to 3' (three prime) forward on one strand matches the sequence reading backward 5' to 3' on the complementary strand with which it forms a double helix.
PCR
polymerase chain reaction (PCR) is a process used in molecular biology to amplify a single copy or a few copies of a piece of DNA across several orders of magnitude, generating thousands to millions of copies
post-transcriptional processing.
process in cell biology by which, in eukaryotic cells, primary transcript RNA is converted into mature RNA.
Gene cloning
process in which a gene of interest is located and copied (cloned) out of DNA extracted from an organism
denaturation
proteins or nucleic acids lose the quaternary structure, tertiary structure and secondary structure which is present in their native state, by application of some external stress
The DNA fragments making up a genomic library are generally contained in
recombinant plasmids of bacteria. B) recombinant viral DNA.
DNA technology
recombinant: A series of procedures used to join together (recombine) DNA segments. A recombinant DNA molecule is constructed (recombined) from segments from 2 or more different DNA molecules.
RFLP analysis can be used to distinguish between alleles based on differences in
restriction enzyme recognition sites between the alleles
recombinant DNA technology
restriction enzyme-production of RFLP C) DNA polymerase-used in a polymerase chain reaction to amplify sections of DNA D) reverse transcriptase-production of cDNA from mRNA E) electrophoresis-separation of DNA fragments
nucleic acid hybridizatio
single-stranded nucleic acids (DNA or RNA) are allowed to interact so that complexes called hybrids are formed by molecules with similar, complementary sequences.
nucleic acid hybridization
single-stranded nucleic acids (DNA or RNA) are allowed to interact so that complexes called hybrids are formed by molecules with similar, complementary sequences.
cloning vector
small piece of DNA, taken from a virus, a plasmid, or the cell of a higher organism, that can be stably maintained in an organism, and into which a foreign DNA fragment can be inserted for cloning purposes
plasmids
small, circular, double-stranded DNA molecule that is distinct from a cell's chromosomal DNA. Plasmids naturally exist in bacterial cells, and they also occur in some eukaryotes. Often, the genes carried in plasmids provide bacteria with genetic advantages, such as antibiotic resistance
post-translational processing
the covalent and generally enzymatic modification of proteins during or after protein biosynthesis. Proteins are synthesized by ribosomes translating mRNA into polypeptide chains, which may then undergo PTM to form the mature protein product.
