manipulating genomes Flashcards
What factors can prevent the maximum rate of PCR?
Temperature damage to the template strand, rejoining of separated strands instead of bonding to primers, lack of primers or free nucleotides, and primers failing to anneal to fragments.
What enzyme is used in PCR to synthesize new strands?
Taq DNA polymerase.
What is the purpose of gel electrophoresis?
To put DNA pieces in size order and read base sequences.
What is DNA sequencing?
Working out the sequence of DNA bases.
How does DNA sequencing relate to predicting polypeptide sequences?
The order of DNA bases codes for the order of amino acids, with each triplet of bases (codon) coding for one amino acid.
What is the significance of high mutation rates in viruses?
Many strains of the virus exist, and DNA sequencing can predict the viral strain for vaccine development.
What is bioinformatics?
It facilitates access to large amounts of data on DNA and proteins, helping identify outbreak sources and vulnerable populations.
What developments have increased DNA sequencing rates?
Nanopore technology, high-throughput sequencing, shotgun sequencing, whole genome sequencing, next generation sequencing, pyrosequencing, and massive parallel sequencing.
What are restriction enzymes also known as?
Endonucleases.
How is a gene inserted into a plasmid?
Complementary bases pair and form hydrogen bonds and phosphodiester bonds using DNA ligase.
How can we check if a bacteria has taken up a modified gene?
Using a marker gene like one that codes for fluorescence or an antibiotic resistance gene.
How is a gene obtained for genetic modification?
By using mRNA to produce complementary DNA via reverse transcription and then making it double-stranded.
What is a concern regarding genetic modification of bacteria?
Increased antibiotic resistance.
How can genes be obtained?
Via chemical synthesis, polynucleotide sequencing, or extracting a gene from an organism using reverse transcriptase on their mRNA.
What is a benefit of bacteria transferring plasmids?
Bacteria can acquire useful genes faster than waiting for mutations.
What is the purpose of polymerase chain reaction (PCR)?
To amplify/make many copies of DNA of different lengths.
How does gel electrophoresis work?
Negatively-charged DNA moves towards the positive electrode, with smaller fragments moving faster.
Why is it helpful that plasmids are small?
It makes it easier for them to be taken up by bacteria, ensuring all offspring are genetically modified.
What is the role of restriction enzymes in DNA digestion?
To cut the genome into smaller fragments and cut vectors for gene libraries.
Why must genomes be fragmented before sequencing?
To improve accuracy and allow division of the job across different labs.
What is recombinant DNA?
DNA combined from two or more different organisms.
What are suitable vectors for gene therapy?
Viruses or liposomes for various applications like spider silk protein or somatic gene therapy.
What do regulatory genes do?
They make repressor proteins and transcription factors that control the expression of structural genes.
What do structural genes do?
They make proteins.
