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4.7b Translation; Synthesizing Protein
Terms in this set (53)
List the required structures for translation.
Ribosomes (composed of rRNA and protein), mRNA, tRNA, and large numbers of free amino acids.
What is the product formed from translation?
Protein is the product formed.
The synthesis of a new protein.
Where does translation take place?
At ribosomes within the cytoplasm.
What is ribosomal RNA?
A functional type of RNA embedded in the structure of ribosomes.
What three sites are associated with a ribosome?
The A (aminoacyl) site, the P (peptidyl) site, and the E (exit) site.
What occurs at the A (aminoacyl) site?
New amino acids are added at this site.
What occurs at the P (peptidyl) site?
The newly forming polypeptide is held in place.
What occurs at the E (exit) site?
The tRNA exits the ribosome.
What rate is mRNA read at?
3 nucleotide bases at a time.
What is the name of each 3 base nucleotide unite in an mRNA molecule?
What 3 nucleotide bases does the start codon contain?
AUG; the signal indicates where protein synthesis begins.
What 3 nucleotide bases does the stop codon contain?
UAA, UAG, or UGA.
What is the 3rd type of RNA?
transfer RNA (tRNA)
How big are tRNA molecules?
Typically they are between 70 and 100 nucleotides.
What shape does a tRNA molecule have?
What two significant regions does tRNA have?
Anticodon, amino acid acceptor end.
What is the group of three nucleotide bases on a transfer RNA molecule in translation?
The anticodon is.
What pairs complementary base codons onto mRNA in translation?
The anticodon does.
What is the function of the 'amino acid acceptor end' in translation?
It is the attachment site of an amino acid to the tRNA, based on the anticodon sequence.
What catalyzes the process of amino acid attachment to the 'amino acid aceptor end' of a tRNA molecule in translation?
How many aminoacyl-tRNA synthtase enzymes are there?
When does the aminoacyl-tRNA synthetase attach amino acids to the correct tRNA?
What determines the amino acid that attaches to the 'amino acid acceptor end?'
The anticodons determines the amino acid.
What is a tRNA with superiorly attached amino acids called?
What three stages does the process of DNA translation share with DNA transcription?
Initiation, Elongation, Termination
What 4 units form the intiation complex in DNA translation?
A small subunit of a ribosome, a large subunit of a ribosome, the newly formed mRNA, and a tRNA.
What 3 nucleotide bases does the tRNA carry?
What is another term for the 3 amino acids (UAC) that charged tRNA carries?
Anticodon is another term for this.
In the initiation phase of translation, the small sub unit moves along the mRNA until it reaches what (2 terms)?
The start codon; AUG
What what are the complementary pairs that start the initiation phase of translation between mRNA and tRNA?
AUG and UAC
What amino acid binds to the Aminoacyl-tRNA synthetase (charged tRNA) before it enters the P-site?
In which site of the large subunit does the initation phase of translation start?
In the P site
In elongation phase of translation, what is the 2nd site that is occupied by a charged tRNA (aminoacyl-tRNA synthetase)?
The A site is.
What bond forms between the charged tRNA's superiorly attached amino acid in the P -site and the charged tRNA's speriorly attached amino acid in the A-site?
A peptide bond forms.
What happens after the peptide bond forms between the two superiorly attached amino acids in the elongation phase of translation?
The tRNA shift from the P and A sites into the E and P sites. The tRNA in the E-site exits, and another charged tRNA molecule enters the now open A-site.
What is being built through the process of elongation?
A polypeptide strand is being created on the superior side of the tRNA through the pairing of amino acids, as per the mRNA's instructions held between the small and large ribosomes, and the 'translation' of the tRNA. Eventually the polypeptide becomes a long protein.
At what point does translation end?
It ends what a stop codon enters the A site.
What are the stop codons for translation? (1)
UAA, UAG, or UGA. (1)
What enters the A-site once a stop codon has been read?
A release factor enters the A-site
What happens when the release factor enters the A-site?
The two subunits of the ribosome are separated from the mRNA and the newly synthesized protein is release.
Can a single mRNA be read by more than one ribosome simultaneously?
Yes, it can be.
What is the term for an mRNA with many ribosomes attached along its length?
How can mRNA be copied very quickly?
By being read simultaneously, becoming a polyribosome.
What might be the potential consequences to protein structure and ability to function if DNA is mutated in a specific gene?
If DNA is mutated in a specific gene, then the mRNA will be transcribed with the mutuation, and the tRNA will translate the mutation; the final protein product will contain the mutation as well and interactions with other parts of the cell will be affected.
What is a codon and an anticodon?
A codon is a group of 3 nitrogenous bases attached to the mRNA molecule. An anticodon is a group of three nitrogenous bases that is attached to a 'charged' tRNA
How is mRNA attached to ribosomes and translated into the language of protein?
In translation, the mRNA molecular strand is enclosed (inferiorly) by a small ribosomal unit and (superiorly) by a large ribosomal subunit. A tRNA molecule with UAC anticodon and attached amino-acid, methionine, inserts itself within the P-site when the ribosomal units 'read' the mRNA's start codon, AUG. As the ribosomal units 'read' the mRNA, charged tRNA molecules continuously inhabit the A-site, shifting the mRNA strands into the E-site to exit; meanwhile the attached amino-acids in the 'amino acid acceptor end' form polypeptide chains that become a new protein.
How many proteins is the human body estimated to carry?
Over 10,000 proteins.
What are some of the functions that proteins serve?
Catalyzing reaction, defense, transport, support, movement, regulation, and storage.
What directs the synthesis of proteins that carry out body functions?
DNA directs this.
What are indirect functions of DNA?
Synthesis of steriod and other lipids, enzymatic pathway of glucose oxidation.
What is DNA sometimes referred to?
The control center of the cell; the 'boss' of the cell.
The genetic code of DNA is the specific instructions to make what biomolecule?
DNA is the specific instructions to make protein, a biomolecule.