Protein Synthesis Flashcards
Where does protein synthesis happen?
Cytoplasm
What is mRNA’s role in protein synthesis?
Carries messages for protein synthesis
What is the first process?
Transcription
What happens in transcription?
Information encoded in DNA is copied to an RNA molecule (one DNA strand used as a template)
The sense strand (coding strand) is the non-template strand that has the same DNA sequence as the RNA strand
The anti-sense strand (non-coding strand) is what the RNA is read off
RNA polymerase binds to a promoter (beginning of a gene) on the DNA
Binds nucleotide triphosphates to the anti-sense strand
mature mRNA has a guanine cap on 5’ and a polyA tail on 3’ and leaves to the cytoplasm
What happens in initiation (translation)?
Components of translation come together (ribosomal units, mRNA, codon-tRNA)
What happens in elongation (translation)?
During elongation , amino acids are brought to the mRNA by the tRNAs and are added one by one to form a polypeptide chain
The tRNA molecule possess a specific sequence of 3-bases (anti-codon), tRNA’s also carry a specific amino acid on the tail end.
When the tRNA anti-codon finds its corresponding codon on the mRNA, it attaches to the mRNA
Another tRNA molecule approaches. Finds its anti-codon–codon compliment and binds.
The two adjacent amino acids carried by the first two tRNAs attach together by peptide bonds with help from the ribosome and using cellular energy in the form of adenosine triphosphate (ATP).
What happens in termination (translation)?
Stop codon enters the ribosome to signal the end of elongation (UGA, UAA or UGA)
The mRNA is released and polypeptide is sent to the golgi apparatus & endoplasmic reticulum for folding and packaging of the protein
