M6 Ch12 Manipulating genomes Flashcards
What is genome sequencing?
Genome sequencing is info about gene location and provides evidence for evolutionary links between organisms
What is genetic engineering?
Genetic engineering involves manipulation of naturally occurring processes and enzymes
What are introns?
Introns are non-coding regions of DNA
What is satellite DNA?
Satellite DNA (short-tandem repeats) = short sequences within introns repeated many times that appear at the same point in chromosomes
What is the human genome project? (HGP)
The Human Genome project = international funded venture to sequence 3 billion bases in 20k+ genes of the human genome - corrections and analyses have been added to results over the years
What is DNA profiling?
DNA profiling = producing an image of the patterns in the DNA of an individual - producing patterns assists in identification of individuals and determining family relationships
What are the key processes that undergo DNA profiling?
Key DNA profiling processes:
-PCR (polymerase chain reaction) = amplifies the DNA by replication
-Electropheresis = seperates DNA fragments according to mass
-Hybridisation = probes added to identify fragments
How to produce a DNA profile?
Producing a DNA profile:
1). Extract DNA
2). Undergo PCR and amplification
3). Digest sample (restriction endonucleases) - cut the strands into small fragments at specific sites
4). Electrophoresis
5). Hybridisation (add DNA probes, RNA complentary binds -> radioactive or fluorescent)
What are the uses of DNA profiling?
Uses of DNA profiling:
-Crime scenes - samples
-Child paternity
-Immigration cases that prove/disprove family relationships
-Establish evolutionary relationships
What is PCR? (polymerase chain reaction)
PCR = artificial way of DNA replication -> amplifies DNA, primers added, DNA is heated and cooled so it can seperate and bind together
Describe the process of PCR. (polymerase-chain reaction)
PCR:
1). DNA sample mixed with DNA nucleotides and DNA polymerase
2).Mixture heated to 95 (denaturation) + bonds between strands break
3). Primers added
4). Temp reduced to 55 (annealing) - primers bind and now double stranded
5). DNA polymerase binding to strands
6). Temp at 72 (optimum for polymerase) adding free nucletotides
Why does polymerase not denature in PCR?
Polymerase does not denature because it is extracted from extremophile bacteria -> can cope with high temperature
What are the stages of electropheresis/DNA profiling?
Electropheresis stages:
1). cells broken down to release DNA (small amount -> amplifiy with PCR)
2). DNA cut into fragments using restriction endonucleases
3). Fragments seperates on bases of site using gel electropheresis
-Fragments injected into wella and electric current applied along gel
Why is gel in electropheresis put into alakaline solution?
Gel is puit into alkali solution to seperate double strands into single ones
Results of gel electropheresis/DNA profiling
Results of gel electropheresis/DNA profiling
-DNA negatively charged so it is attracted to positive end of gel
-Shorter DNA fragments move faster than longer fragments
-DNA seperated on basis of size
Hybridisation of DNA profiling
Hybridisation = radioactive or fluorescent DNA probes added to DNA fragments on membrane
-Probes bind to complementary strands under pH and temp conditions
What is DNA sequencing?
DNA sequencing = the process of determining the precise order of nucleotides within a DNA molecule
Stages of DNA sequencing
Stages of DNA sequencing:
1). DNA mixed with primer, DNA polymerase, excess of nucleotides and terminator bases
2). Mixture placed in thermal cycler (96C=seperates strands, 50C=primers anneal to strand)
3). 60C=polymerase builds new strands by adding nucleotides with complementary base to single strand
4). When terminator base added, a strand terminates until all possible chains produced
5). DNA fragments serperated by length in capillary tubes - the fluorescence on terminater bases determine final base of each fragmentq
Benefits of DNA profiling
Benefits of DNA profiling:
-Identification of individuals and family relationships
-use in crime scenes
-proving or disproving immigration cases
Limitations of DNA profiling
Limitations of DNA profiling:
-Can be too dependent on in comparison to other evidence in crime scenes
-Mistakes can be made as it is done on multiple levels
-Potential contamination of DNA samples from other organisms
What is genetic engineering?
Genetic engineering is the manipulation of the genome to achieve a desired outcome
Basic principles= isolating a gene fur a desired characteristic in one organism into another using a suitable vector)
What is meant by transgenic?
Transgenic is an organism carries a gene from one organism - often called a genetically modified organism (GMO)
Process of genetic engineering
Process of genetic engineering:
1 isolating the desired gene 2. Formation of a recombinant DNA 3. Transforming the vector
Isolating the desired menu as the first step of genetic engineering
By restriction endonuclease (DNA profiling) at specific base sequences
Sticky ends = unevenly it DNA where desire gene is easier to insert
