Recombinant DNA Technology Flashcards
What is biotechnology?
The use of microorganisms to make practical products
What is recombinant DNA technology?
Genetic engineering
Describe donors and recipients in the context of genetically modified organisms (GMOs) (2)
- Genes are isolated from a donor organism
- Genes are inserted into the genome of a recipient organism
What was the first drug manufactured using recombinant DNA technology?
Insulin
What is reverse transcription?
Synthesis of RNA into DNA
Retroviruses carry their genome as ______
RNA
Reverse transcriptase is a ______
DNA polymerase enzyme
What is the function of reverse transcriptase?
Synthesis of cDNA from an mRNA template
How is complementary DNA (cDNA) made?
Through reverse transcriptase
How are restriction enzymes produced?
Bacteria cut DNA at restriction sites
What characteristics make restriction enzymes ‘restriction endonucleases’? (2)
- Recognizing palindromic sequences
- Restricting bacteriophages from multiplying
Restriction sites are specific nucleotide sequences called ______
Palindromes
Why do bacteria produce restriction enzymes in nature?
To stop bacteriophages from multiplying
Describe EcoRI restriction enzymes (2)
- Make staggered cuts of 2 strands of DNA
- Create sticky ends
Describe Hindlll and Smal restriction enzymes (2)
- Cut both strands of DNA at the same point
- Create blunt ends
It is more difficult to make recombinant DNA from ______ fragments
Blunt-ended
What are vectors in the context of recombinant DNA technology?
Nucleic acid molecules
What are some examples of nucleic acid vectors? (2)
- Viral genomes
- Plasmids
What selectable marker gene do vectors contain?
Antibiotic resistance gene
How does the selection for vectors work? (2)
- A medium contains the antibiotic
- Cells containing the recombinant plasmid can grow on the medium
What is the goal of recombinant DNA?
Insert a useful gene into a cell to get a new phenotype
What are ‘CRISPR’s? – what does the acronym stand for?
- Clustered
- Regularly
- Interspaced
- Short
- Palindromic
- Repeats
CRISPR DNA sequences act as a ______
Primitive immune system
CRISPR DNA sequences provide protection from ______ from viruses
Prokaryotes
What are CRISPR repeats?
Stretches of palindromic DNA
How long are CRISPR repeats?
25 - 50 bp long
What are CRISPR spacers?
Sequences from viruses that invaded the prokaryote
How long are CRISPR spacers?
20 - 80 bp long
Describe the process in which bacteria acquire DNA sequences (2)
- A bacteriophage infects the cell
- A piece of viral DNA is added as a spacer
Describe the process in which CRISPR RNAs (crRNAs) mediate defense against viral infections (2)
- The spacer is transcribed into crRNA
- crRNA guides Cas to the bacteriophage
What specific role do CRISPR-associated enzymes (Cas) play in the defense against pathogens / future diseases?
Disables the virus by cutting its DNA
Describe how CRISPR technology can be used in so-called ‘genome editing’
RNA identifies a specific piece of DNA that is inserted into a new strand
By whom, and in what year, was the polymerase chain reaction (PCR) developed?
Kary Mullis in 1983