3.8.3 Using genome projects

Question 1

What is the genome?

Answer 1

the entire set of genetic material (DNA) present in an organism

Question 2

What does the genome include?

Answer 2

both coding and non-coding genes

Question 3

What is the proteome?

Answer 3

full range of proteins that a cell or organism is able to produce at a given time, under specified conditions

Question 4

Why is the proteome more useful to sequence?

Answer 4

it is the functional product of the genome

Question 5

How is Sanger sequencing used to determine the genome of an organism?

Answer 5

1. DNA is cut into fragments using restriction enzymes
2. Fragments are replicated by PCR (with primers, dNTPs and ddNTPs)
3. ddNTPs act as terminators preventing addition of nucleotides to specific strand
4. Results in chain termination, with lots of fragments of different lengths
5. Gel electrophoresis separates fragments by length
6. Sequences of bases can be visualised (from coloured tags on ddNTP) from position of fragments
   =complete base sequence of organisms DNA
   =GENOME

Question 6

What is the importance of identifying genome of simpler organisms (e.g. prokaryotes)?

Answer 6

identify proteins that act as antigens on surface of pathogen, use protein in vaccine

Question 7

Why is it more difficult to determine genome and proteome of complex organisms (e.g. humans) than simple organisms (e.g. prokaryotes)?

Answer 7

-genome contains non-coding genes
-many genes (e.g. human genome = 20,000 genes)