Exercises: Genetic engineering techniques
What is the polymerase chain reaction (PCR) and what is it used for? Name two practical situations in which amplifying DNA is essential.
What is the polymerase chain reaction (PCR) and what is it used for? Name two practical situations in which amplifying DNA is essential.
What are restriction enzymes, from which organisms are they obtained, and what is their function in genetic engineering?
What are restriction enzymes, from which organisms are they obtained, and what is their function in genetic engineering?
What is a transgenic organism? Give an example and outline, in general terms, how it is produced.
What is a transgenic organism? Give an example and outline, in general terms, how it is produced.
Put the steps required to clone a human gene in bacteria in order and justify the sequence: introduce the recombinant plasmid into the bacterium, cut the gene and the…
Put the steps required to clone a human gene in bacteria in order and justify the sequence: introduce the recombinant plasmid into the bacterium, cut the gene and the plasmid with the same restriction enzyme, join the gene to the plasmid using DNA ligase, select and multiply the transformed bacteria.
CRISPR-Cas9 allows genome editing with high precision. Explain simply what role guide RNA plays and what role the Cas9 protein plays in this technique.
CRISPR-Cas9 allows genome editing with high precision. Explain simply what role guide RNA plays and what role the Cas9 protein plays in this technique.
A research group aims to synthesize the peptide hormone insulin in the bacterium Escherichia coli. To do this, they directly isolate the insulin gene from the nuclear…
A research group aims to synthesize the peptide hormone insulin in the bacterium Escherichia coli. To do this, they directly isolate the insulin gene from the nuclear DNA of human pancreatic cells and insert it into a bacterial plasmid alongside an efficient E. coli promoter.
- a) After introducing the plasmid into the bacteria, they find that an aberrant, inactive polypeptide of incorrect size is synthesized. Explain why eukaryotic genomic DNA cannot be properly expressed in a bacterium, referencing gene structure and RNA processing machinery.
- b) Design the biotechnological strategy to solve this problem: indicate which molecule you should isolate as the initial template, what type of specific synthetic primer you would use taking advantage of a post-transcriptional modification of that molecule, and which enzyme of viral origin you will use to synthesize the first strand of complementary DNA (cDNA).
- c) When comparing the sequence of the obtained cDNA with that of the initial nuclear gene, it is observed that the cDNA is much shorter and lacks the original human promoter sequence. Explain why this happens and justify how the bacterium is made to transcribe this cDNA once cloned into the plasmid.