DNA/Gene Sequencing

Question 1

What is DNA sequencing?

Answer 1

The process of deterring the nucleic acid sequence - the order of nucleotides in DNA.

Question 2

Process of Sanger sequencing.

Answer 2

1- 4 reaction dishes.
2- DNA polymerase , 4 bases, primer added.
3- Add DNA that has been cut using restriction enzymes into a fragment.
4- Add modified bases , which are radioactive- 1 per dish.
5- DNA polymerase adds bases onto the primer and produces many new strands.
6- ddNTP terminates chain -> fragment ends.
7- This produces many fragments which are all different lengths.
8- separated during electrophoresis.
9- Nucleotide at end of each fragment read according to radioactive label.

Question 3

What does high throughput sequencing do?

Answer 3

Generates and analyses millions of sequences per run, allowing researchers to sequence, resequence and compare data at fast rate.

Question 4

Process of pyrosequencing.

Answer 4

1- cut up DNA fragments mechanically using nebuliser.
2- Degraded into single strands and immobilised.
3- Primer added.
4- Incubated with enzymes : DNA polymerase, ATP sulphurylase,
5- Incubated with substrates: APs and luciferin.
6- Incubated with activated base .

Question 5

What has gene sequencing allowed?

Answer 5

• Allowed genome comparisons between individuals in a species and between members do different species.
• Allowed for the sequence of amino acids in proteins to be predicted.
• Allowed the development of a new field of biology - synthetic biology.

Question 6

What does bioinformatics do?

Answer 6

• Develops and uses computer software to analyse, store and organise biological data.
• DNA, RNA, protein.
• Data is universal and shared internationally.
  E.g. sequencing data used to study genotype, phenotype correlations to treat disease.

Question 7

What does comparative gene mapping do?

Answer 7

• Identifies importance of different genes.
• See tiny changes in genes cause diff features.
• Comparing species identifies evolutionary relationships.

Question 8

What is synthetic biology?

Answer 8

• Knowing DNA sequence -> you can find out the a.a sequence.
• Designs and builds biological devices and systems.
  E.g. synthetic new proteins, biosensors, new medicine.

Question 9

Uses of synthetic biology.

Answer 9

1- Building biological systems from artificially made molecules.
2- Redesign biological systems to perform better and include new molecules.
3- Designing new biological systems and molecules that don’t exist already.

Question 10

What can pharmocogenetics do?

Answer 10

• Can figure out if a drug will work by testing someone’s genome.
• Drs can prescribe a drug that works rather than “one fits all”

Question 11

How to sequence genome?

Answer 11

1- mapped using microsatellites to identify genes.
2- microsatellites are short pieces of repetitive sequences of 3-4 bases pairs.
2- Samples of genome sheared into small sections.
4- Placed in BAC (bacterial artificial chromosomes) and bacteria (e.coli) to make clone libraries.