8.3 Using genome projects Flashcards
What is the genome?
The complete set of genetic information contained in the cells of an organism.
What is genome sequencing?
Identifying the DNA base sequence of an individual. This allows us to determine the amino acid sequence of the polypeptides coded for by that DN
What is the proteome?
The complete set of proteins that can be produced by a cell.
Can we directly translate the genome into the proteome?
In simple organisms, yes. In complex organisms, due to the presence of non-coding DNA and regulatory genes, it is much harder to obtain the proteome.
Give an application of sequencing the proteome in simple organisms.
Identifying potential antigens for use in vaccine production.
Give some applications of genome sequencing.
Comparing genomes between species to determine evolutionary relationships.
Genetic matching.
Personalised medicine.
Synthetic biology.
How have sequencing methods changed over time
Used to be a manual process, however now it has become automated. A reaction mixture is created and after the process is complete, a machine reads the base sequence
In Europe, viruses have infected a large number of frogs of different species. The viruses are closely related and all belong to the Ranavirus group.
Previously, the viruses infected only one species of frog.
(a) Suggest and explain how the viruses became able to infect other species of frog.
1.
Mutation in the viral DNA/RNA/genome/genetic material;
Altered (tertiary structure of the) viral attachment protein;
Allows it/attachment protein/virus to bind (to receptors of other species);
Name two techniques the scientists may have used when analysing viral DNA to determine that the viruses were closely related.
The polymerase chain reaction
Genetic/DNA fingerprinting
(Gel) electrophoresis
DNA/genome sequencing;
Determining the genome of the viruses could allow scientists to develop a vaccine.
Explain how.
1- could identify proteins that derive from the genetic code
2- they could identify potential angitfens to use in vaccines
How does genome sequencing benefit prokaryotic research?
Genome sequencing allows researchers to determine the proteome (sequences of amino acids in proteins) in prokaryotes.
Why is it easier to determine the proteome of prokaryotes?
Prokaryotic genomes do not contain introns, regulatory genes, or non-coding regions, making it easier to determine the proteome.
Why is it difficult to determine the proteome of eukaryotes?
Eukaryotic genomes contain non-coding DNA (including introns) and regulatory genes, making it more difficult to determine the proteome.
What are the key principles of DNA sequencing?
Use restriction enzymes to break DNA into smaller fragments.
Use PCR to replicate the fragments.
Add dideoxynucleotides into the PCR mixture - these act as terminators, preventing further addition of nucleotides to a specific strand.
Separate fragments of different lengths using gel electrophoresis.
Visualise the sequence of bases from the position of fragments (coloured tags or different PCR runs and lanes for each base).
What do gene sequencing methods only work on?
fragments of DNA
How can we sequence the entire genome of an organism?
chop the DNA into smaller pieces. Smaller pieces are then sequenced and put back into order to give sequence of whole genome
What was the Human Genome Project 2003?
first time when the entire sequence of the human genome was mapped
Why is it easier to map determine the proteome from the DNA sequence of their genome from bacteria?
because they don’t contain non coding parts of FNA
Why can it be useful to determine the proteome of bacteria?
can identify protein antigens on the surface of disease causing bacteria and viruses and be able to develop vaccines to prevent the disease
Why is it harder to translate the genome of humans than bacteria?
because human DNA contains non coding sections.Also contains regulatory proteins which determine when genes for particular proteins should be switched on/ off.
What are regulatory proteins?
proteins that determine when the gene that codes for that particular protein should be switched on/ off
Why do regulatory genes make it harder to translate genomes into proteones?
Hard to determine the parts that code for proteins among the non coding and regulatory DNA
How have sequencing methods changes over time?
Previously sequencing methods were labour intensive, expensive and could only be done on a small scale. Now they are automated, more cost effective and done on a larger scale.
What do the new faster and larger ways to sequence mean?
can sequence the whole genome much more quickly
What does determining the gnome of simpler organisms allow?
the sequences of the proteins that derive from the genetic code to be determined
In more complex organisms, why is it harder to translate the genome?
due to the presence of non-coding DNA and regulatory genes
Main way sequencing methods have changed?
become automated
In more complex organisms like humans,
the presence of non-coding DNA and of regulatory genes means that knowledge of the genome cannot easily be translated into the proteome.
Sequencing methods
are continuously updated and have become automated.
