Insulin Production - Introduction

Question 1

What is insulin?

Answer 1

A protein (hormone) that helps control blood glucose levels.

Question 2

What type of protein organisatiojn level is insulin?

Answer 2

Quarternary Structure - Composed of 2 polypeptide chains

Question 3

What is a plasmid?

Answer 3

A small, circular, double stranded DNA molecule. Separate to cell’s chromosomal DNA.

Question 4

Plasmids naturally exist in which cells?

Answer 4

Bacterial cells

Question 5

How many plasmids can bacteria carry?

Answer 5

None to multiple

Question 6

Why are plasmids considered vectors?

Answer 6

They can act as vehicles that transport/trasnfer foreign DNA into bacterial cells

Question 7

How do plasmids multiply/replicate?

Answer 7

• They are self-replicating
• Contain an origion of replication where DNA replication of plasmid begins.
• Plasmids can replicate independantly to chromosomal DNA

Question 8

What is a non-recombinant plasmid?

Answer 8

A plasmid that has not undergone DNA editing. Contains only original plasmid DNA.

Question 9

What is recombinant plasmids.
Express recombinant plasmids in terms of insulin as well.

Answer 9

• Recombinant plasmids have their DNA edited.
• Recombinant plasmids contain gene of interest (insulin)

Another gene of interest could also be lacZ gene

Question 10

How many genes encode for human insulin?

Answer 10

2 genes.

As two polypeptides are produced.

Question 11

What does the lacZ gene produce?

Answer 11

B-galactosidase

Question 12

What is B-galactosidase?

Answer 12

An enzyme that can convert substrate X-gal to go from being colourless to blue

Question 13

What are anti-biotics?

Answer 13

Drugs and compounds that are harmful against bacteria

Question 14

What is ampicilin?

Answer 14

An anti-biotic

Question 15

What do plasmids contain in relation to ampicilin?

Answer 15

They carry an ampicilin resistance gene.

Question 16

What is the difference between transformed and untransformed bacteria?

Answer 16

• Transformed bacteria - Bacteria that have taken up a plasmid
• Untransformed bacteria - Bacteria that do not possess plasmid

Question 17

What is tetracycline?

Answer 17

An ani-biotic

Question 18

What are the two methods of making untransformed bacteria become transformed bacteria by taking up plasmids?

Answer 18

1. Heat Shock
2. Electro-poration

Question 19

Breifly explain how Heat Shock can transform bacteria

Answer 19

1. Plasmids and Bacteria are placed in test-tube
2. Transferred from an ice-cold solution to 42 degrees celsius for less than a minute
3. This increases fluidity and permeability of plasma membrane.
4. Now chance of bacteria taking in plasmids increases.

Question 20

Briefly explain how Electroporation can transform bacteria

Answer 20

1. Bacterial cells and plasmids placed together in test tube.
2. Solution goes through electric current
3. This alters plasma membrane to become more permeable.
4. Now, chance of bacteria taking in plasmids increases.

Question 21

Bacterial colonies are grown on what?

Answer 21

Agar plates and then incubated

Question 22

What were some previous methods of getting insulin?

Answer 22

From pigs

Question 23

What are some problems with sourcing insulin form pigs

Answer 23

• Allergies
• Cofnlicts with some religious beliefs
• Unethical
• Pigs are not always high in numbers year round