DNA sequencing Flashcards
define genome
all the genetic material an organism contains
the human genome consists of …….. base pairs and …… genes
3 billion
20,000
define proteome
all of the proteins a cell can produce
where can a proteome be derived from?
genetic code if genome sequence is known
- only in simple organisms
what is the purpose of DNA sequencing projects?
read genomes of many organisms which allows DNA screening to identify medical problems
what is the importance of identifying a proteome?
allows identification of antigens for use in vaccine production
why can the proteome not be derived from genetic sequences in more complex organisms?
non coding DNA and regulatory genes prevent the genome being easily translated into a proteome
what is a terminator base?
a base which stops DNA synthesis
- A,T,C,G
summarise, in 6 stages, the process of DNA sequencing
- DNA polymerase, primer, excess nucleotides, terminator bases and DNA are all mixed together in a thermocycler
- DNA polymerase adds complementary bases to create new DNA
- terminators are added randomly to terminate DNA synthesis at different points on each replicating strand
- this continues until all DNA chains are produced with a terminator at each base
- terminators are labelled with different fluorescent colours to identify them
- DNA fragments are separated using gel electrophoresis according to length
describe how the DNA sequence is worked out after DNA sequencing process
by fragment length and base colour
what is high through sequencing?
processing and sequencing many DNA fragments simultaneously
describe the first DNA sequencing
- done by hand
- designed to read the base sequences of viral and bacterial DNA
- used radioactive markers and gel electrophoresis to separate sections of DNA
what are the weaknesses of the first DNA sequencing techniques?
- time consuming
- only study small sections of DNA at a time
