8.5 - Triplet code and Non-coding DNA Flashcards
(12 cards)
what happens before the pre-mRNA exits?
the introns are spliced
What do eukaryotic cells transcribe during transcription?
transcribes the whole gene (including exons and introns) - produces pre-mRNA molecules
what are non-coding DNA found as?
introns within genes
these can separate exons
Where can non-coding sections of DNA be found?
between genes as they contain the same base sequences repeated multiple times
What are non coding sections of DNA?
doesn’t code for any amino acids
Universal meaning for genetic code
- all organisms almost use the same code
- same codons code for the same amino acids
what does degenerate mean?
multiple codons can code for the same amino acid
what is the benefit of having start and stop codons?
reads the DNA correctly (code is non-overlapping) - produces the correct sequence of amino acids for the correct function
How does a ribosome know when to start joining amino acids and stop?
some of the triplet codes for the start and stop signals
tells the cell where individual genes start and stop
what are the triplets of bases known as?
codons
and codes for one amino acid
What does three bases code for?
one amino acid
What is a gene?
a sequence of nucleotide bases in a DNA molecule that codes for the production of a specific sequence of amino acids, that in turn make up a specfic polypeptide
