Mutations and Genetic disorders Flashcards
What are mutations?
Random changes to chromosomes, genes or DNA
what’s the genome?
it is the organisms entire heredity information (everything that makes you)
what’s bioinformatics?
computer and statistical analysis used to compare DNA sequence data
how can computers identify base sequences?
By looking for sequences similar to known genes
What are the single gene mutations?
Substitution, insertion, deletion
What single gene mutations are point mutation and what’s frameshift mutation?
Point mutation is substitution and frameshift mutation is insertion and deletion
What do each of the single gene mutations do?
Substitution- replace one of the DNA nucleotides
Insertion- adds a DNA nucleotide in the sequence
Deletion- Removes a DNA nucleotide from the sequence
What are the different types of substitutions?
Missense, nonsense and splice-site
What is this an example of: C A T C A T C A T?
DNA bases
Picture a start and stop codon?
Roughly
AUGAUCUAA
MET-ILE-SER
codon. Stop codon
What’s missense?
Picture the example
A type of substitution where one amino acid is replaced. A single nucleotide is substituted which results in amino acid codon being replaced with another.
What is nonsense?
Roughly picture it
Single nucleotide substitution which results in amino acid codon being replaced with premature stop codon (result in shorter protein)
What is splice-site?
Results in some introns and or exons being retained in mature transcript. Splicing is a controlled by specific nucleotide sequences at locations called splice sites (if mutation happens at one, intron may be kept in error) and opposite happens when site becomes splicing at wrong points
What are the frameshift mutations?
Insertion and deletion
What happens during insertion and what does this do?
A nucleotide is inserted which shifts pre-existing nucleotides, altering DNA, RNA and amino acid sequences (protein structure altered)
In insertion and deletion, what is always altered?
DNA, RNA and amino acid sequence and protein structure
What does deletion do and what does this cause?
Removes one or more nucleotides from sequence, shifting DNA base sequence and alters DNA, RNA, amino acid and protein structure
What’s the difference between point mutation and frameshift mutation?
Point mutation only affects one amino acid (substitution) where as frameshift has a bigger effect on other amino acids (insertion and deletion) and there is major structure effect on protein/ amino acid)
What’s the difference between single gene mutations and chromosome mutations?
Single gene mutations only affect sequence of DNA nucleotides. Chromosome is alerting at nucleotide level (genes are changed) (like a big level up from)
What is all the chromosome mutations?
Inversion, translocation, duplication and deletion
What’s deletion (chromosome mutation)?
A section of the chromosome is removed
What is translocation?
A section of a chromosome is added to another chromosome (not it’s homologous partner)
What is inversion?
When part of a chromosome if reversed
What is duplication in terms of chromosome mutations?
Section of chromosome is added to homologous partner and a duplicated gene may mutate and evolve to a new function (can be very bad)
