DNA Technology/Engineering

Question 1

What is a Restriction Enzyme?

Answer 1

It is an enzyme that cuts up DNA on recognition of a certain short sequence.

There are many difference Reconition enzymes all looking for different sequence patterns.

Question 2

What is meant by the term ‘Recognition Site’?

Answer 2

This is the area that the reaction enzyme identifies as the start of the sequence.

Question 3

What is meant by ‘blunt ends’ or ‘sticky ends’?

Answer 3

This is the way in which the enzyme cuts through the DNA strand. Blunt ends means that the Enzyme cuts straight through the two strands or ‘sticky ends’ means it staggers the cut.

Question 4

What is meant by the term ‘Clevage site’?

Answer 4

This is where the Restriction enzyme cuts through the DNA.

Question 5

What happens when a ‘sticky end’ needs to reattach to other nucleotides?

Answer 5

The ends will attach to of nucleotides by complementary base paring but only if they have been cut by the same enzyme.

Question 6

What enzyme reattaches the DNA?

Answer 6

DNA Ligase. It recreats the phosphdiester bonds

Question 7

What is DNA Enginerring?

Answer 7

The modification of DNA using a single trait to creat a disired change.

Question 8

What is another name for Genetic Engineering?

Answer 8

Recombinant DNA Technology

Question 9

What is the name given to a gene that has been genitically altered?

Answer 9

Genetically Modified Organisum

Question 10

What are the 3 different types of modification that can be done?

Answer 10

1. Insert a foreign gene from one organisum to another
2. Alter an existing gene to change its products
3. Change the gene replication rate

Question 11

Explain the term ‘Recombinant DNA’

Answer 11

This is DNA that has been merged with other DNA. Re combined

Question 12

What are the 5 stages used to create Recombinant DNA

Answer 12

1. Isolation
2. Insertion
3. Transformation
4. Identification
5. Growth/Cloning

Question 13

Thinking about Genetic Engineering what would be the vector and what would be the host?

Answer 13

The vector would be the plasmid the host would be the bacteria

Question 14

What methods are used to transfer Gene’s into the host?

Answer 14

Heat Shock - incubate at 0^oC and then suddenly rised to 40^oC. This causes some cells to take up the plasmids. Also known as Transformation.

Electroporation - Cells subjected to high-voltage pulse temporarily disrupting the membrane

Question 15

Breifly run through the process of Genetic engineering

Answer 15

1. Identify, using restriction enzyme, the segment of DNA required to combined with other DNA. Cut out this area
2. Insert the cut piece of DNA into the opended vector (plasmid) along with the antibiotic resistant marker.
3. DNA Ligase bonds the 2 peices of DNA together
4. The plasmids and bacteria are warmed in a test tube together wating the bacteria to take up the plasmids.
5. Bacteria are then spread on an antibiotic agar aiming to kill those bacteria that do not have the antibiotic resistant marker on the new plasmids.

Question 16

What does PCR stand for?

Answer 16

Polymerase Chain Reaction

Question 17

What is the aim of PCR

Answer 17

To replicate the targeted area of DNA for further sampling or research

Question 18

Describe the 3 steps to PCR techique

Answer 18

1. Denaturing -The DNA is heated to 90^oC to uncoil and unzip the helix
2. Annealing - The temp is lowered allowing the primers to attach to the forward and reverse ends of the targeted DNA
3. Extension - DNA Polymerase attaches the free nuleotides to the inital DNA strand.
4. The steps are repeated 2 more times to isolate the targeted DNA.

Question 19

Describe the Thery behind DNA Finger printing

Answer 19

The DNA is cut up by an enzyme seeking out a certain code sequence. The DNA is cut everytime this sequence is found. This will be different of each individual. When put through electrophresis that individuals grid will look different to the other persons unless related.

There are many different enzymes,

Question 20

In DNA Fingerprinting what does MRS stand for?

Answer 20

Microsatellite Reapt Sequences

These are the small repeating squences that a specific enzyem will look for when cutting the DNA

Question 21

How does Electrophoresis work?

Answer 21

Given that DNA is slightly Negative in charge, DNA is placed in a tray made of Agarose gel that conducts electricity.

The DNA is drawn towards the positivly charged Anode causing a grid like patterns used in identification.

Question 22

In electrophoresis what ingredient is used to Visualise the Sample?

Answer 22

Ethidium Bromide. It shows up in UV Light.

Question 23

What is the name given to the short bits of DNA cut by Restriction enzymes?

Answer 23

Restriction Fragments

Question 24

If the DNA was cut by one enzyme, would a different enzyme reattach the sticky ends?

Answer 24

No- it needs to be the same enzymes.