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When a ribsome reaches a stop codon, the translation process stops and a protein is released.
Nannie Keeling
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How is the nucleotide seguence in the mRNA translated into a polypeptide sequence?
As we all know, mRNA undergoes translation to form a polypeptide sequence. Besides the mRNA, there are still the tRNA ( transfer RNA ) and rRNA ( ribosomal RNA ). All these three types of RNA are essential in determining the polypeptide sequence. This is the because, mRNA only acts as a messenger. A messenger to bring the information from the DNA to the ribosome to synthesis protein. the tRNA transports the required amino acid to form the polypeptide refering to the mRNA while the rRNA builds a site for the polypeptide synthesis to occur. For translation to occur, the essential components are required : tRNA with it's anticodons to the start codon - UAC - ( start codon = AUG- methionine). the subunits of the ribosomal RNA and the mRNA that needs to be translated. i)the tRNA with the correct anticodons binds to the start codon. ii) the next tRNA recognizing the next codon locates itself on the ribosome and the first tRNA is transferred by ribosome. iii) Once the amino acid are in place, peptide bonds are formed between them and a polypeptide chain is formed. the first tRNA leaves the ribosome while the next tRNA takes it's place. As another tRNA recognizes the next codon, it locates itself on the ribosome once more. iv) Translation goes on until the ribosome reaches either one of the stop codon. -- UAA / UAG/ UGA.. found on the mRNA. v) When the ribosome arrives at the stop codon, translation stops. The ribosome splits to it's two sub units, and the newly synthesized polypeptide chain is released from the mRNA. vi) the tRNA and rRNA can be reused to form new polypeptides on other mRNA strands.
What is the termination signal?
It stops the codon, so it cannot continue.
How does DNA make a copy of itself in order to travel outside to make protein?
DNA is double stranded, in the shape we know as the "double helix." One strand of DNA is the coding strand, while the other is called the complementary strand. The coding strand is what has the protein codes, the complementary strand just bonds to that strand. DNA is also located inside the nucleus, which is protected by a nuclear membrane. This nuclear membrane is porus, but the double helix is too big to fit through these pores. So, the DNA has to be copied into mRNA (messenger ribonucleic acid.) Now, DNA is made up of nucleotides, all of which are either Adenine, Thymine, Guanine, and Cytosine; or just A, T, G, and C. A and T always pair together in the double helix, and G and C always pair together. But, the mRNA has ribonucleotides. There are still A, G, and C; but instead of a T bonding to an A, a Uracil, or U, will bond to all the A nucleotides. Okay, confusing basics, but heres the fun part. The DNA molecule "unzips," or the two strands pull apart when its time to make a protein. Then, a molecule called an mRNA polymerase will attach to the coding strand of the DNA and start "reading" it. Once it reaches the sequence "TAC" (remember the little parts that make up the DNA strand,) it will start to attach the ribonucleotides. This "TAC" is know as a start codon, because it tells the mRNA polymerase to start. Now, the mRNA polymerase will bond "AUG" to the "TAC". Then mRNA will continue to bond it's ribonucleotides to the corresponding nucleotides of the coding strand of DNA, until it reaches a "stop" codon. This stop codon is either ATT, ATC, or ACT on the DNA; which becomes UAA, UAG, or UGA on the mRNA. This is when the mRNA stops pairing ribonucleotides to the DNA nucleotides, because the code for the protein is complete. Every set of 3 nucleotides in between the start and stop codons are called a codon, and they code for one specific amino acid that will make up the protein. Now that the mRNA strand has been made, it is sent out of the nucleus because it is single-stranded, and can fit through the pores. This process of making the mRNA is called Transcripiton. But how can the protein be made? As soon as the mRNA strand exits the nucleus, a ribosome, or rRNA molecule, bonds to it. This ribosome "reads" the mRNA, and begins to attach "anti-codons" to the mRNA codons (remember a codon is 3 ribonucleotides that code for an amino acid.) The anti-codons and the amino acids come in a "package" called a tRNA, or transfer RNA, molecule. This consists of the anti-codon that will pair up to the mRNA codon, and an attached amino acid that is specific to the mRNA codon. For example, the start codon AUG will pair to the anti-codon UAC, and AUG codes for the amino acid methionine; so the tRNA molecule will have UAC at the base, and methionine attached at the top. The ribosome will do this to each codon within the strand, so each codon has an anti-codon and amino acid attached. But, ribosomes can only fit 3 codons inside them at any time, so it has to move down the mRNA 3 codons at a time. As a codon exits the ribosome after being attached to it's tRNA molecule, the anti-codon part of the tRNA breaks off and the amino acid attaches to the other amino acids using a peptide bond. So the ribosome leaves behind a string of amino acids bonded together using peptide bonds. To find out which codons on the mRNA code for which amino acids, you need to use an "amino acid wheel," which is a wheel that is read by looking at the innermost circle and finding the ribonucleotide that the codon begins with, then looking in that section to find the second ribonucleotide in the codon, then looking in that small section of the outermost circle to find the last ribonucleotide of the codon, which will then show you the protein. This chart is attached in the image below. Anyways, once the ribosome reaches a stop codon on the mRNA, it stops attaching the tRNA molecules, and the result is all the amino acids that correspond to the codons, bonded together to create the finished protein! This process of creating the protein is called Translation, so the entire process from DNA to protein is called Transcription and Translation.
What happens to ribosomes during protein synthesis?
Protein synthesis take place on ribosomes.They provide surface for it.
Is the nasal cavity continuous?
No. It stops when it reaches the esophogus.
What happens after the ribosome reaches the start codon?
When a ribsome reaches a stop codon, the translation process stops and a protein is released.
What halts translation in DNA?
In the translation of a DNA a stop Codon will help to put a stop to the process of translation.There are three stop codons used in the process when a ribosome reaches one of the Codon it stops.
Where does the process of translation do in mRNA?
The newly spliced mRNA binds to a ribosome. tRNA molecules migrate towards the ribosome, these tRNA molecules carries a specific amino acid. The ribosome allows two tRNA molecules into the ribosome at a time. The tRNA molecules have complementary anti-codons to the codons present on the mRNA strand. Two tRNA move into the ribosome and their anti-codons join to complementary codons on the mRNA strand. As one molecule leaves the ribosome, its amino acid forms a peptide bond with an amino acid on the adjacent tRNA molecule, with the help of ATP and an enzyme. As the ribosome moves along the the mRNA strand, a polypeptide chain is created. The ribosome stops reading the mRNA strand when it reaches a stop codon.
Which mRNA codons will start the process of translation?
If you're referring to stop codons, then there are three: UAA, UAG and UGA. They do indeed stop translation, though I wouldn't say they halt ribosomes. Stop codons code for a releaser enzyme, one that fits the A site of the ribosome, but does not carry an amino acid. This enzyme cuts the bond between the polypeptide and the last tRNA.
Synthesis of a protein stops when?
it stops when an amino acid is missing from the diet
How is the nucleotide seguence in the mRNA translated into a polypeptide sequence?
As we all know, mRNA undergoes translation to form a polypeptide sequence. Besides the mRNA, there are still the tRNA ( transfer RNA ) and rRNA ( ribosomal RNA ). All these three types of RNA are essential in determining the polypeptide sequence. This is the because, mRNA only acts as a messenger. A messenger to bring the information from the DNA to the ribosome to synthesis protein. the tRNA transports the required amino acid to form the polypeptide refering to the mRNA while the rRNA builds a site for the polypeptide synthesis to occur. For translation to occur, the essential components are required : tRNA with it's anticodons to the start codon - UAC - ( start codon = AUG- methionine). the subunits of the ribosomal RNA and the mRNA that needs to be translated. i)the tRNA with the correct anticodons binds to the start codon. ii) the next tRNA recognizing the next codon locates itself on the ribosome and the first tRNA is transferred by ribosome. iii) Once the amino acid are in place, peptide bonds are formed between them and a polypeptide chain is formed. the first tRNA leaves the ribosome while the next tRNA takes it's place. As another tRNA recognizes the next codon, it locates itself on the ribosome once more. iv) Translation goes on until the ribosome reaches either one of the stop codon. -- UAA / UAG/ UGA.. found on the mRNA. v) When the ribosome arrives at the stop codon, translation stops. The ribosome splits to it's two sub units, and the newly synthesized polypeptide chain is released from the mRNA. vi) the tRNA and rRNA can be reused to form new polypeptides on other mRNA strands.
What is the termination signal?
It stops the codon, so it cannot continue.
What are the steps taken to translate a 9-base DNA strand into an amino acid sequence?
There are a huge number of steps involved in this process, but briefly it goes like this: # Transcription factors bind to DNA and promote binding of RNA polymerase # RNA polymerase binds in complex with transcription factors # Transcription is initiated and RNA polymerase uses free NTPs, complementary to the antisense strand of DNA to create an RNA copy of the DNA. # The mRNA leaves the nucleus - some modification may take place # Translation factors bind mRNA # Ribosome binds to mRNA # tRNA brings amino acids to ribosome # Ribosome begins translation at methionine start codon - matching anticodon on tRNA to triplet codons on mRNA to pair correct amino acid to the mRNA code # Ribosome stops translation at stop codon # Ribosome/mRNA/tripeptide complex will dissociate
Which process stop when rna polymerase comes to a terminator?
Transcription is the process that stops when RNA polymerase is terminated.
How does DNA make a copy of itself in order to travel outside to make protein?
DNA is double stranded, in the shape we know as the "double helix." One strand of DNA is the coding strand, while the other is called the complementary strand. The coding strand is what has the protein codes, the complementary strand just bonds to that strand. DNA is also located inside the nucleus, which is protected by a nuclear membrane. This nuclear membrane is porus, but the double helix is too big to fit through these pores. So, the DNA has to be copied into mRNA (messenger ribonucleic acid.) Now, DNA is made up of nucleotides, all of which are either Adenine, Thymine, Guanine, and Cytosine; or just A, T, G, and C. A and T always pair together in the double helix, and G and C always pair together. But, the mRNA has ribonucleotides. There are still A, G, and C; but instead of a T bonding to an A, a Uracil, or U, will bond to all the A nucleotides. Okay, confusing basics, but heres the fun part. The DNA molecule "unzips," or the two strands pull apart when its time to make a protein. Then, a molecule called an mRNA polymerase will attach to the coding strand of the DNA and start "reading" it. Once it reaches the sequence "TAC" (remember the little parts that make up the DNA strand,) it will start to attach the ribonucleotides. This "TAC" is know as a start codon, because it tells the mRNA polymerase to start. Now, the mRNA polymerase will bond "AUG" to the "TAC". Then mRNA will continue to bond it's ribonucleotides to the corresponding nucleotides of the coding strand of DNA, until it reaches a "stop" codon. This stop codon is either ATT, ATC, or ACT on the DNA; which becomes UAA, UAG, or UGA on the mRNA. This is when the mRNA stops pairing ribonucleotides to the DNA nucleotides, because the code for the protein is complete. Every set of 3 nucleotides in between the start and stop codons are called a codon, and they code for one specific amino acid that will make up the protein. Now that the mRNA strand has been made, it is sent out of the nucleus because it is single-stranded, and can fit through the pores. This process of making the mRNA is called Transcripiton. But how can the protein be made? As soon as the mRNA strand exits the nucleus, a ribosome, or rRNA molecule, bonds to it. This ribosome "reads" the mRNA, and begins to attach "anti-codons" to the mRNA codons (remember a codon is 3 ribonucleotides that code for an amino acid.) The anti-codons and the amino acids come in a "package" called a tRNA, or transfer RNA, molecule. This consists of the anti-codon that will pair up to the mRNA codon, and an attached amino acid that is specific to the mRNA codon. For example, the start codon AUG will pair to the anti-codon UAC, and AUG codes for the amino acid methionine; so the tRNA molecule will have UAC at the base, and methionine attached at the top. The ribosome will do this to each codon within the strand, so each codon has an anti-codon and amino acid attached. But, ribosomes can only fit 3 codons inside them at any time, so it has to move down the mRNA 3 codons at a time. As a codon exits the ribosome after being attached to it's tRNA molecule, the anti-codon part of the tRNA breaks off and the amino acid attaches to the other amino acids using a peptide bond. So the ribosome leaves behind a string of amino acids bonded together using peptide bonds. To find out which codons on the mRNA code for which amino acids, you need to use an "amino acid wheel," which is a wheel that is read by looking at the innermost circle and finding the ribonucleotide that the codon begins with, then looking in that section to find the second ribonucleotide in the codon, then looking in that small section of the outermost circle to find the last ribonucleotide of the codon, which will then show you the protein. This chart is attached in the image below. Anyways, once the ribosome reaches a stop codon on the mRNA, it stops attaching the tRNA molecules, and the result is all the amino acids that correspond to the codons, bonded together to create the finished protein! This process of creating the protein is called Translation, so the entire process from DNA to protein is called Transcription and Translation.
What happens to ribosomes during protein synthesis?
Protein synthesis take place on ribosomes.They provide surface for it.
How are ribosomes recycled?
After translation stops and the polypeptide chain has been released, the ribosome needs to dissociate off of the mRNA transcript. A Ribosome Recycling Factor (RRF) will insert itself into the A-pocket of the ribosome (this A-pocket still contains a stop codon). Elongation Factor G (EF-G) then binds to the RRF. This binding stimulates the release of the two tRNAs that are in the P and E pockets of the ribosome. The RRF and the EF-G are then displaced from the ribosome. The mRNA is also released and the two halves of the ribosome are allowed to dissociate. Afterwards, the small ribosomal subunit is either bound by IF1 an IF3 or elF1 and eLF1A depending on the organism being a prokaryote or eukaryote. These proteins block tRNAs from entering into its E and A pockets.
