Producing DNA fragments Flashcards
What is an organism that contains recombinant DNA called?
A genetically modified organism
What is the combination of DNA from two different organisms called?
Recombinant DNA
The process of making a protein using the DNA technology of gene transfer and cloning involves 5 stages. What are they?
ISOLATION of the DNA fragments that have the gene for the desired protein, INSERTION of the DNA fragment into a vector, TRANSFORMATION which is the transfer of the the DNA into suitable host cells, IDENTIFICATION of the host cells that have successfully taken up the gene by the use of gene markers and GROWTH of the population of host cells
Name the two enzymes used to identify and isolate a gene from the DNA
Reverse transcriptase and restriction endonucleases
What does reverse transcriptase do?
It catalyses the production of DNA from RNA, which is the reverse of the more usual transcription of RNA from DNA
Describe the process of using reverse transcriptase to isolate a gene
A cell that readily produces the protein is selected and large amounts of the relevant mRNA that they contain are extracted. Reverse transcriptase is then used to make DNA from RNA which is known as complementary DNA (cDNA) because it is made up of the nucleotides that are complementary to the mRNA. To make the other strand of DNA, the enzyme DNA polymerase is used to build up the complementary nucleotides on the cDNA template
What are restriction endonucleases?
Enzymes that cut up viral DNA
At what point on the DNA double strand does restriction endonucleases cut the specific sequence of bases?
A recognition sequence
What are blunt ends?
Straight edges that are produced when a cut occurs between two opposite base pairs
What are sticky ends?
Where the DNA has not been clean cut and therefore has longer overhanging bases
What is a palindrome?
A segment of double stranded DNA in which the nucleotide sequence of one strand reads in reverse order to that of the complementary strand
