Translation Flashcards
protein synthesis
- The amino acid sequence is determined by the specific order of nucleotides in the gene
- code consists of three sequential bases (triplet code)
Codons
Nucleotised read in groups of three
4x4x4= 64 possibilities
Amino acids have more than one codon
be able to read chart, not memorize
Role of RNA
RNA is the “go-between” molecules that links DNA to proteins
where is RNA formed
Nucleus
tRNA have…
special areas that contain a specific triplet code (anticodon) that allows each tRNA to carry only a specific amino acid
Ribosome composition
composed of RNA and proteins which fold together to form the final structure
Translation Initiation
- small Ribo subunit bind with mRNA and guides it to start codon AUG
- proteins called initiation factors bring large subunit that completes the translation initiation complex
simplified: The ribosome and other factors scan the mRNA’s 5’ UTR to find the AUG initiator codon.
Translation elongation
- the ribosomes move along mRNA reading codon and adding assoc Amino Acids to growing poly peptide chain
Translation Termination
A stop codon (UAA, UAG, or UGA) is encountered, and the polypeptide is released from the ribosome
Ribosomal recycling
the ribosome dissociates into subunits and is ready to start again
mRNA degredation
After many ribosomes have finished translating, the mRNA is degraded so the nucleotides can be reused
Protein modification
The newly made polypeptide usually needs to be folded and modified before it can become an active protein