Genetic Engineering

Question 1

STEP ONE - How would you obtain the required gene? - Using mRNA

Answer 1

• Obtain the mRNA for the gene from the cell where that gene is being expressed. e.g. human insulin obtained from the pancreas
• to the mRNA, add some DNA nucleotides and the enzyme reverse transcriptase
• this enzyme catalyses the opposite reaction to transcription
• allows for the conversion of mRNA into single strand of DNA (cDNA)
• DNA is made double stranded by adding DNA nucleotides, primers and DNA polymerase
  two copies of the gene are made

Question 2

STEP ONE - How would you obtain the required gene? - automated machine

Answer 2

• Gene can be synthesised in a lab using an automated machine by adding DNA nucleotides, DNA polymerase and provide a sustainable temperature

Question 3

STEP TWO - what happens when 2 sections have been cut off?

Answer 3

• When 2 sections of DNA have been cut off with the same restriction enzyme, giving them complementary sticky ends, they can be joined together using DNA ligase
• when the pieces join, it is called Recombinant DNA

Question 4

What are marker genes?

Answer 4

• Chosen gene is inserted into a plasmid, one marker gene is also inserted at the same time

Question 5

STEPS 3 - What are vector areas?

Answer 5

• Vectors area is added to the solution containing the chosen host cell
• DNA does not easily cross the cell membranes

Question 6

STEP 3 - What is Heat shock treatment?

Answer 6

• This makes the walls and the mebrane more porous allowing for the uptake or recombinant vector?

Question 7

STEP 3 - What is electoporation?

Answer 7

High voltage pulse applied to a host cell to disrupt the cell surface membrane

Question 8

STEP 3 - What is electtrofusion?

Answer 8

• Electrical fields are used to introduce DNA into the host cells

Question 9

STEP 4 - Hint: host cells

Answer 9

Indentifying which host cells have been successful int the taking up the new gene