DNA - The Genetic Code Flashcards
Where is the genetic material stored?
In the nucleus of a cell.
What are genes? [1 mark]
A short section of DNA.
Each gene codes for a specific protein.
What is DNA?
A polymer of nucleotides wound in a double helix structure.
What is a genome?
The entire genetic information/material of an organism.
What can mutations in DNA cause?
A different amino acid being produced - changes tertiary structure of protein - changes function of protein.
State the positive outcomes of knowing the whole human genome [2 marks]
> Can search for genes linked to disease.
> Understand & treat inherited disorders.
> Tracing migration patterns.
What is an exon?
A region of the genome that ends up within an mRNA molecule.
They are the CODING sequences in DNA.
What is an intron?
A region within a gene but doesn’t remain in the final mRNA molecule.
They are NON-CODING sequences in DNA (junk DNA)
What is a locus?
The position of the gene on the DNA.
What is an allele?
A different version/form of the same gene.
What are the features of the genetic code?
> It is DEGENERATE.
> It is UNIVERSAL.
> It is NON-OVERLAPPING.
What is a triplet of bases known as?
A codon.
What does it mean by the ‘code is degenerate’, and what are the advantages?
Means most amino acids are coded for by MORE THAN 1 triplet of bases (codon).
+ If there’s a point mutation (change in 1 base), then potentially the same amino acid may be produced - this is called a silent mutation.
Bc diff triplets may sometimes produce the same amino acid so the protein doesn’t change.
What does it mean by the ‘code is universal’, and what are the advantages?
The SAME triplet (codon) will code for the SAME amino acid in EVERY living organism.
+ This made genetic engineering possible
(e.g. inserting human insulin gene into bacteria)
What does it mean by the ‘code is non-overlapping’, and what are the advantages?
Each base is only part of 1 triplet so each triplet is separate with no overlap.
+ A point mutation would only affect 1 TRIPLET and so only 1 amino acid is affected, MINIMISING the impact.
