Karteikarten
Manipulating genomes
Karten in diesem Stapel (13)
- 1Describe Sanger's approach to DNA sequencing4 dishes, each contain a solution with each of the 4 bases, ATC&G, as well as DNA polymerase. To each dish a modified version of one of the bases was added. The bases were modified so that once they annealed to the complementary strand, no more bases could be added, and were labelled with a radioactive isotope. Thousands of DNA fragments of different lengths were produced in each dish, and separated by electrophoresis.
If the shortest, 1 base long sequence had the modified thymine at the end, the first base is T. If the two-base fragments had cytosine at the end, it was TC, etc.
This way the whole DNA strand could be sequenced. - 2List advantages and disadvantages of Sanger's methodEfficient and safe, but very time consuming and costly.
- 3Describe the process of pyrosequencingA long length of DNA is cut into fragments of 300-800 base pairs, and then split into ssDNA. A sequencing primer is added for DNA polymerase to work, and the DNA is then incubated with DNA polymerase, ATP sulfurylase, luciferase, apyrase, and the substrates adenosine 5' phsphosulfate and luciferin. ATP, TTP, CTP & GTP is added one at a time. When one of the activated nucleotides (nucleotides with 2 extra phosphoryl groups) such as TTP is incorporated onto a complementary strand of DNA, the 2 phosphoryl groups are released as pyrophosphate. The prophosphate is converted to ATP via ATP sulfuryase in the presence of APS. In the presence of ATP, luciferase converts luciferin to oxyluciferin, which generates visible light which can be detected. If more than one of the bases join in a row, more light is generated. Unincorporated nucleotides are degraded by apyrase, and then the next nucleotide is tested.
- 4What is bioinformatics?A branch of biology that handles storing and processing the large amounts of data generated from DNA sequencing
- 5List applications of gene sequencingComparing human genes to animal genes to find evolutionary relationships, comparing genes of species, comparing genes between individuals, finding causes of genetic disease, predicting the amino acid sequences of proteins, synthetic biology, etc.
- 6What is synthetic biology?An interdisciplinary science concerned with designing and building useful biological devices and systems.
- 7Describe the process of DNA profiling1. DNA is obtained from an individual
2. The DNA is cut at specific recognition sites into DNA sequences of varying lengths by restriction enzymes
3. The fragments are separated by gel electrophoresis
4. A banding pattern can be seen
5. The DNA to which the individual's is being compared undergoes steps 2 & 3
6. The banding patterns of the two DNA sequences are then compared - 8List applications of DNA profilingForensic science, maternity/paternity disputes & analysis of disease
- 9What is the PCR?It is a way of amplifying DNA for analysis
- 10Describe the process of PCR1. The DNA sample is mixed with DNA nucleotides, primers, Mg ions & the enzyme taq DNA polymerase
2. The mixture is heated to 95°C to split the DNA into single stranded DNA
3. The mixture is cooled to 68°C so the primers anneal at one end of each strand
4. Taq DNA polymerase molecules bind to the end with the primer
5. Temperature is raised to 72°C to keep the DNA as single strands
6. Taq DNA polymerase catalyses the addition of DNA nucleotides, starting from the primer and proceeding in the 5' to 3' direction
7. When the enzyme reaches the other end of the DNA molecule, a new double strand of DNA has been generated.
8. Cycle repeats many times - 11List applications of PCRTissue typing, detection of oncogenes, detecting mutations, identifying viral infections, monitoring the spread of infectious disease, forensic science, research
- 12What is a DNA probe?A short single stranded length of DNA that is complementary to a section of the DNA being investigated, and is tagged with a radioactive isotope or fluorescent dye
- 13What is a microarrayA number of different probes on a fixed surface. Applying fragments of the DNA under investigation to the surface can reveal the presence of specific alleles that match the DNA probes, allowing scientists to search for specific gene mutations in a DNA sequence.
Informationen
- Beschreibung
- AS - Level Biology Flashcards on Manipulation genomes, created by Ben Levett on 13/04/2017.
- Erstellt von
- Ben Levett
- Aufrufe
- 18
- Bewertung
Mehr zu DNA Sequencing and Profiling