Translation Flashcards
(13 cards)
What is translated during translation
The base sequence code of the mRNA is translated.
What dictates the order of amino acids in a polypeptide?
The base sequence code of the mRNA dictates the order of amino acids in a polypeptide.
What bonds join amino acids?
Peptide bonds
How does a ribosome ‘read’ the base sequence code of the mRNA?
The ribosome reads in base triplets known as codons.
How many amino acids does one codon produce?
One codon only produces one amino acid (1:1).
What is a codon and an anti-codon?
A codon is a sequence of three nucleotides in mRNA, while an anti-codon is a sequence of three nucleotides in tRNA that binds to its complementary codon.
How many different combinations of codons are there?
64
How many ‘STOP’ codons are there?
There are 3 ‘STOP’ codons that do not code for an amino acid and completely terminates the process of translation.
How many ‘START’ codons are there?
There is only 1 ‘START’ codon with the base sequence of AUG. It codes for the amino acid ‘Methionine’.
What is the purpose of transfer RNA (tRNA)?
tRNA codes for the anti-codon and carries one amino acid to the ribosome.
What is needed for translation to occur?
- mRNA
- Ribosome enzyme and rRNA complex
- 61 different tRNA molecules (with attached amino acid)
What is the purpose of rRNA complex?
Maintains structure of ribosomes and creates peptide bonds between amino acids.
What are the 3 stages of translation?
- Initiation: Ribosome seeks and docks at the first AUG (‘START’ codon)
- Chain Elongation:
- tRNA molceules move to the mRNA/ribosome and ‘deposit’ their amino acid according by their anti-codon.
- Amino acids continue to be added to each other to from an elongating polypeptide. - Chain Termination:
- Finally, one of the ‘STOP’ codons, UAG, UAA, or UGA is reached.
- If there is no tRNA available, a release factor binds in the A site instead resulting in the ‘release’ of the polypeptide from the ribosome from mRNA.
