Biotechnology Flashcards
What are biotechnology techniques; outline all 3.
The broad study of the applications used in modifying and sampling DNA and how it may be expressed in a genome. - DNA sequencing/profiling and recombinant DNA.
Outline the process of DNA Sequencing.
Determination of exact order of nucleotides in a DNA sequence.
- DNA segment is extracted from the cell.
- PCR starts sequencing reaction.
- DNA stands are sorted by size using gel electrophoresis.
- Read by computer displaying nucleotide sequence.
Outline the process of the PCR (polymerase chain reaction).
Create multiple copies of a segment of DNA:
Denaturing - sample heated to 95°c. Breaks H-bonds between nucleotides, separating the two DNA strands.
Annealing - sample heated to 60°c, primers (short synthetic DNA fragment) is added to DNA. Primers bind to complementary base sequence on separated DNA strands. P acts as a start point as DNA polymerase starts synthesising strand at P.
Elongation - sample heated to 74°c (optimum for polymerase). Polymerase binds to primers and reads the DNA code, building a complementary strand.
Outline the process of DNA Profiling.
Identifies the natural variations found in every organisms DNA.
- Using enzymes to rid of short tandem repeats (STR’s) - non-coding DNA.
- PCR is used to make multiple copies of the DNA segment.
- Gel electrophoresis is used to sample the DNA segment from length.
Outline the process of Recombinant DNA.
Direct modification of an organism’s genome, inserted from another’s to display specific traits in a species.
- Restriction enzymes cut DNA (plasmid) at specific points (usually 4/8 base pairs) - now the recognition site.
- Foreign DNA is inserted into the cell - to join the complementary DNA strands exposed from the cuts - joining from the sticky ends of the nucleotides to form the remaining strand.
- DNA ligase acting as glue joins the nucleotides together.
- Now, this cell represents a modified genome; displaying specific traits, making it a transgenic organism.
Outline process/function of ddNTP (dideoxynucleotide triphosphate) in DNA Sequencing.
A fluoro-tagged synthetic nucleotide with no OH group (ddNTP) is added to the growing DNA strand during DNA sequencing:
- ddNTP stops elongation of sequence - no OH group for the next ddNTP to attach.
- Creates a small DNA segment that is run through the gel electrophoresis method.
- By comparing DNA sequences - changes alleles, mutations can be detected via. similarities and differences.
- Observing how closely related species are.
What is Gel Electrophoresis - and the electrophoresis DNA bonding?
Gel Electrophoresis:
- DNA samples are mixed with dye and injected into wells in a sheet of poron (jelly-like).
- Electric current passes through wells and poron - with positive end attracting fragments with the smaller travelling further.
Bond:
- If fragments line up next to each other from their lanes showing relation in STR’s.
What is a Restriction Enzyme?
Have the ability to cut DNA molecules at specific sequences of 4-8 base pairs called recognition sites.
Straight Cut - clean break of two DNA strands - no free nucleotides.
Staggered Cut - unclean break - free nucleotides (sticky ends); can combine with sections of DNA with complementary ending.
How do Plasmids clone?
1) Gene of interest (DNA frg.) is isolated from human tissue cells.
2) Human DNA and Plasmid are treated with a restriction enzyme - produce identical sticky ends.
3) An appropriate plasmid vector is isolated from a bacterial cell.
4) Restriction enzyme cuts plasmid at a single recognition site.
5) DNA’s mixed together and add enzyme DNA ligase to bind sticky ends.
6) Recombinant Plasmid is introduced into bacterial cell - adding DNA to bacterial culture - some bacteria make a plasmid from the solution.
Outline vectors for gene cloning and their properties.
A self-replicating DNA molecule (plasmid/viral DNA) used to transmit a gene between organisms.
Vector Properties:
- able to replicate inside the host.
- have one/more sites where restriction enzyme can cut.
- have some genetic marker - allows them to be easily identified.
Outline 3 applications we use biotechnology (recombinant DNA) in agriculture.
Environmental Factors: increase the resistance of plant against EF - soil salinity, temperature, pests, etc.
Vitamin/Mineral Content: increase V/M content of plant - golden rice is a GMO with increased vitamin-A and beta-carotene.
Yield: Increase Y/biomass used as a food source - grains fruits, seeds. In animals with potentially - increased muscle mass, milk output, wool quality, etc.
Outline how Goats are able to produce spider silk in their milk?
Spiders genome is inserted into that of a goats genome; in the gal-glands to produce spider silk in its milk. Example of Recombinant DNA.
What is a Transgenic Organism?
An organism from a cell of which foreign DNA has been introduced; Spider-Goat.
