Manipulating genomes Flashcards
what is DNA sequencing used for
DNA sequencing is used to work out the sequence of nucleotides in a section of DNA.
what are the steps of sanger sequencing
Step 1: Create copies of DNA fragments
Step 2: Create complementary DNA strands
Step 3: Analyse the DNA by separating it according to length
what is needed to create complementary DNA fragments
DNA polymerase, DNA primers, DNA nucleotides, terminating DNA nucleotides
What is the name given to the range of methods which have allowed very rapid, cheaper sequencing of DNA?
high-throughput sequencing
what are the 3 main benefits of DNA sequencing
- It enables genome-wide comparisons between individuals and species.
- It allows us to predict the amino acid sequences of genes, which in turn allows us to predict the tertiary structure of the polypeptide the gene codes for.
- It is used for synthetic biology, which modifies existing DNA sequences.
what is genetic engineering
Genetic engineering is the process of isolating a gene from one organism and placing it into another.
Why is the genetically modified organism able to translate the newly added gene?
because the genetic code is universal
what type of therapy is genetic engineering
gene therapy
what is somatic gene therapy
the gene is introduced into body cells (also called somatic cells). These cells will eventually die, and so this treatment has short-lived effects and the gene won’t be inherited.
what is germ-line therapy
the gene is introduced into germ cells (also called sperm and egg cells). This means all the genes in the offspring will be altered, so the treatment has long-term effects and will be inherited.
what is pharming
Pharming is when an animal’s DNA is altered so that they produce human proteins for medicine or they develop human diseases for pharmaceutical testing.
what does a patent mean for a modification
It prevents other companies from replicating their modification for a limited time.
what are the two ways of producing DNA fragments
restriction endonuclease and reverse transcriptase
where does the restriction endonuclease cut the DNA molecule
at a specific set of bases known as the recognition sequence
which bonds do restriction endonucleases break between the nucleotides
phosphodiester bonds
how does reverse transcriptase work
A second way that DNA fragments can be produced involves mRNA. An enzyme called reverse transcriptase first adds DNA nucleotides to an mRNA molecule. This forms a new strand called complementary DNA. After this strand is built, an enzyme destroys the mRNA molecule.
Finally, a second DNA strand is built by an enzyme called DNA polymerase. This produces a complete DNA fragment.
What is a gene mutation?
A gene mutation is a change in the base sequence of DNA.
what are the external factors that increase rate of mutations called
mutagenic agents
what is a deletion mutation
when a nucleotide base is removed from a DNA sequence
what is a substitution mutation
when a nucleotide base is swapped out for another one
what is an insertion mutation
when a nucleotide is added to the DNA sequence
what is a frameshift
a change in the sequence of base triplets in a gene
what types of gene mutation lead to a frameshift
insertion and deletion
what are the possible effects of mutations on proteins
mutations which change a proteins primary structure could lead to change in the bonds of its tertiary structure, this may result in a non-functioning protein which is harmful to the organism or result in a new protein which could be beneficial to the organism
