Translation: PROTEIN SYNTHESIS Flashcards
Process that occurs after ___________.
transcription
Translation occurs where?
Occurs in the cytoplasm, with the help of ribosomes and transfer RNA.
Translation refers to ..
putting something into a different language.
In translation, the message on the
mRNA will be translated into a _____________ _______.
polypeptide chain.
What is the
anticodon found on the tRNA carrying tyrosine?
mRNA codon is 5’UAU3’ or 5’UAC3’ for tyrosine
What amino acid is
found on the tRNA with an anticodon of CAU?
remember, that is 3’CAU5’
Every tRNA carries one specific…..
amino acid
tRNA is the “________” molecule in protein synthesis
adaptor
_________ is the last stop or the end of the line (terminus) to which amino acid is coupled.
CCA-3’
Why doesn’t tRNAs follow one-gene/one polypeptide?
Because the tRNA itself, is transcribed from a gene
but it is not translated into a protein product.
What is a polysome and polyribosome?
A number of ribosomes translating the same transcript.
What is the A (acceptor) site?
where tRNA
brings in new aa
What is the P (peptide) site?
where peptide bonds form between aa’s in growing polypeptide
First tRNA is brought into __ ______ – carries Met
P site
Initiation in prokaryotes vs eukaryotes
Initiation can occur at internal AUG codons in prokaryotic mRNA
Initiation in eukaryotes can ONLY occur at first AUG codon of the 5’ cap.
What is a codon?
A codon is a sequence of three nucleotides in mRNA that codes for a specific amino acid or signals the start or stop of protein synthesis.
A peptide bond forms
between the 2 …….
amino acids
The new reading frame results in the…
wrong amino acid sequence and formation of a truncated protein
What is a truncated protein?
A truncated protein is a shortened protein that results when its synthesis stops prematurely due to a genetic mutation or error, often missing key functional parts.
In the cell, at what site manufactures proteins?
Ribosomes
What does tRNA do?
delivers aa’s to a polypeptide building site (the ribosome)
amino acid activation and tRNA charging is facilitated by..
aminoacyl-tRNA synthase
ribosomes have 2 sites that bind tRNA:
A and P
The ribosomes moves along the mRNA in the….
5’ to 3’ direction.
What is a reading frame?
A reading frame in protein synthesis is the way nucleotides in mRNA are grouped into sets of three (codons) during translation.
Each codon specifies one amino acid, and the correct reading frame ensures the right protein is made. Shifting the reading frame changes what?
the codons and can result in a completely different or nonfunctional protein.
Describe the structure of tRNA.
single stranded that folds into 2D
clover leaf
3D form is produced when the leaf
twists
What is the enzyme responsible for attaching
an amino acid to the tRNA??
aminoacyl-tRNA synthase
