Recombinant DNA technology

Question 1

What is a GMO?

Answer 1

Genetically modified organism

Question 2

What is recombinant DNA

Answer 2

The method of joining 2 or more DNA molecule to create a hybrid

Question 3

What has recombinant DNA allowed for?

Answer 3

It has allowed for genes to be altered and transferred between organisms

Question 4

What is a transgenic organism?

Answer 4

A GMO

Question 5

Briefly outline the stages of recombinant DNA technology

Answer 5

1. Isolation of DNA fragments (genes for the desired protein)
2. Insertion of DNA fragments into vector
3. Transformation of DNA into suitable host cell
4. Identification of host cells that have successfully taken up the gene
5. Growth/cloning of the population of host cells.

Question 6

Briefly describe isolation and the 3 ways it is possible

Answer 6

• DNA is a long continuous molecule, the desired gene needs to be located, isolated and cut from the DNA to be inserted into another organism.
• Reverse transcriptase
• Restriction endonucleases
• Gene machine

Question 7

Describe reverse transcriptase

Answer 7

• Take a cell that produces the desired protein and extract the mRNA
• Reverse transcriptase combines free DNA nucleotides to the mRNA which forms cDNA (complementary)
• The cDNA is a single stranded molecule, the use of DNA polymerase makes it double stranded, this double stranded DNA is the required gene

Question 8

Describe restriction endonucleases

Answer 8

• Enzymes that cut DNA naturally occur in bacteria, cut up and destroy viral DNA
• There are different types of RE: each one has different active site shape that is complementary to a specific DNA sequence. This is known as recognition site and is where the enzyme will cut the DNA.
• Blunt ends: cuts in between 2 opposite pairs
• Palindrome (sticky ends): cuts in staggered fashion leaving unpaired bases known as sticky ends. This is beneficial as DNA joins easier

Question 9

Describe gene machine

Answer 9

• This is done by scientists, the rest is done by a computer which makes it very quick
  1. Examine proteins to identify amino acid sequence and from this work out the mRNA and DNA sequence

2. The sequence is put into the computer and checked for biosafety and biosecurity (ethical/harmful)
3. The computer creates small sections of overlapping single strands of nucleotides.
4. They then get joined together to make 1 copy of the gene.
5. PCR replicates gene and constructs complimentary strand
6. Genes are checked, errors are rejected