Translation Flashcards
(104 cards)
What is the first step in protein synthesis?
Translation
-the code contained in a mRNA is translated into a particular series of amino acids to form a polypeptide
What are the mRNAs, tRNAs, and RRNAs synthesized during transcription used for?
To complete translation
What does the protein coding region of an mRNA contain?
A series of nucleotide triplets
What is each Triplett called?
Codon
How many possible combinations of nucleotides are there?
64
How are the nucleotides read?
5’ to 3’
In what direction is the protein synthesized?
From its N-terminus to its C-terminus
Start codon
AUG
-for all protein synthesis and defines the reading frame
Reading frame
The serious of triplets that make the subsequent codons
WHat does AUG code for, besides being the start codon?
Methionine
Are all AUGs start codons?
No, but all start codons are AUG
How many codons does methionine have?
1
Internal codons containing AUG
They are methionine codons, not additional start codons
The first AUG encountered reading 5’ to 3’
Defines the start codon and the subsequent reading frame
Stop codons
- do not encode an amino acid
- UAG, UAA, UGA
___ of the 64 codons define as amino acid
61
-AUG defines an amino acid, but 3 are stop codons and do not code for AA
Codon specificity
Each codon is specific to a certain amino acid
Codons-universal
Genetic code defines the same amino acids in almost all organisms
Codon redundancy
Each amino acid may have more than one codon
How many codons do each amino acid have?
Between 1 and 6
Codon: nonoverlapping and commaless
- code is defined as a continuous series of 3 basses, no overlap and no “punctuation” (no codon is read more than once and no bases are skipped or repeated)
- should start at beginning and read through to the end
Do stop codons code for amino acids?
Nope
START DOES!
What are some examples of single nucleotide changes?
- Silent mutation
- Messenger mutation
- Nonsense mutation
Single nucleotide mutations
Point mutation