3.8.3. Using Genome Projects

Question 1

Genome

Answer 1

Entire set of DNA, including all of the genes, in an organism.

Question 2

Sequencing projects

Answer 2

Technology = sequence (read) genomes of a variety of organisms (bacteria + humans).

Question 3

Gene sequencing methods only work on…

Answer 3

fragments of DNA. Sequence entire genome = chop into smaller pieces first. Sequence smaller pieces and then put back into order to give entire sequence of whole genome.

Question 4

Proteome

Answer 4

All the proteins an organism makes

Question 5

Simple organisms e.g. bacteria

Answer 5

Some parts of genome = code for specific proteins; some are non-coding. Simple organisms don’t have much non-coding DNA so its easier to determine their proteome from the DNA sequence of their genome.

Question 6

Why is it useful to determine the proteome of simple organisms?

Answer 6

Med research + development
E.g. identify protein antigens on surface of disease causing bacteria + viruses = helps in development of vaccines.
Sequence the genome of the bacteria, identify the antigens, develop vaccine against the disease.

Question 7

How do vaccines work?

Answer 7

Contain antigens that cause your body to produce memory cells. Infected by a pathogen with the same antigens = memory cells recognise it and divide to produce antibodies against it = don’t get ill.

Question 8

Summarise simple organisms

Answer 8

Determining the genome of simpler organisms allows the sequences of the proteins that derive from the genetic code (the proteome) of the organism to be determined.
This may have many applications, including the identification of potential antigens for use in vaccine production.

Question 9

Complex organisms

Answer 9

Large sections of non-coding DNA. May also contain complex regulatory genes = more difficult to translate genome into proteome.

Question 10

What are regulatory genes?

Answer 10

Found in complex organisms - determine when the genes that code for particular proteins should be switched on and off.

Question 11

Why is it difficult to translate genome to proteome in complex organisms?

Answer 11

Hard to find the bits that code for proteins among the non-coding and regulatory DNA.

Question 12

Sequencing methods are continuously updated…

Answer 12

and have become automated.
Past: labour intensive, expensive, small scale
Now: automated, cost-effective, large scale
Newer, faster techniques = scientists can sequence whole genomes much more quickly.

Question 13

Pyrosequencing

Answer 13

Recently developed technique - can sequence around 400 million bases in 10 hours (super fast)