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Does the last nucleotide in a codon have less specificity than the others and if so why?
Yes, this is true (generally speaking). In many cases there are two different codons that differ at the third position yet code the same amino acid.
I hypothesize that the reason that this is so is that nature has naturally selected the codons to be resistant to certain transition and transversion mutations.
transition mutation = purine to purine or pyrimidine to pyrimidine
transversion mutation = purine to pyrimidine or pyrimidine to purine
What else can I help you with?
How long does your first period go on for?
Average is 5-7 days. Everyone is different. Some will last 3 days. Others may last 10.
How many prime numbers have 5 as there last digit?
one 5 all others are divisible by 5 at least
How old are clocks?
Some clocks are hundreds of years old (and still fully functional); others were only made last week.
What is the last line that is shorter than the others called on a staff?
The last line that is shorter than the others on a staff is called a "ledger line." Ledger lines are used to extend the range of the staff, allowing notes above or below the standard five lines to be notated clearly. They are typically used for notes that fall outside the regular staff notation.
What is more significant figures of 1 2.0 3.00 4.000?
The last one has more sig figs than the others.
Put the following structures in order from smallest to biggest, Chromosome, Genome, Nucleotide Base, Codon, Gene, Cell Nucleus?
atombase subunitnucleotidesgenechromosomenucleuscellAnd also, DNA is totally sweet if you learn about it. Ya 'know? Just take the time to read your book instead of Google searching everything, ok Justin?!
What kind of mutation is this ugu-ccg-GAA-cga to ugc-cgg-GAA-cga?
The sequence TGA-GCC-ATG-A is changed in 2 places to become TGA-GCA-CAT-GA.When one base is changed, it is called a point mutation.In this case, a GCC in the DNA has been changed to a GCA. This would mean the mRNA codon (coded for by this DNA) would change from CGG to CGU.Both of these codons code for the same amino acid - Arginine. Therefore this type of point mutation is known as a silent mutation.The extra C that appears would be called an addition mutation, which is a type of frameshift mutation.
Why is UAG codon called amber codon?
The UAG codon is a special kind of codon called a stop codon. There are three types of stop codons: amber, ochre, and opal. UAG is an mRNA codon that is specific for the amber stop codon. The amber codon was named after Harris Bernstein, then a Caltech graduate student, whose last name means "amber" in German. The related link points to an article that discusses the history a bit more.
In the polymerization of DNA a phosphodiester bond is formed between a phosphate group of the nucleotide being added and what of the nucleotide in the polymer?
The phosphate group of the incoming nucleotide joins the 3'-hydroxyl group of the last nucleotide in the growing DNA chain to form a phosphodiester bond.
What is the final step in the natural process for making proteins?
The last step is reading the termination codon which will release the protein.
If an mRNA is made up of 60 bases how many codons does it contain and how many amino acid does it code for?
A codon is exactly three bases long, so an mRNA strand with 60 bases would contain 20 codons. The first codon will encode for methionine (this is called the "start" codon) and the last codon will be a "stop" codon, which does not encode for an amino acid. Thus, an mRNA strand of 60 bases will code for 19 amino acids. Keep in mind, it is possible for a stop codon to be anywhere on the mRNA strand, and when a stop codon reaches the ribosome, translation must stop. For example, if an mRNA strand contained 30 codons, and the 15th were a stop codon, the mRNA would only code for 14 amino acids and then be done. The other 15 codons would go untranslated.
What meaning do the first and last codons have for protein synthesis?
Codons are used for making amino acids. Some codons will tell the ribosomes to start tell the tRNA to make the amino acids or to stop making amino acids. I like to think of the start/initiator/promoter codon(AUG) as a capital letter in a sentence and the stop/terminator codons(UAA, UAG, and UGA) as periods in a sentence.
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.
How many codons are present on the mRNA strand?
There are 6 codon here. Look at the letters and put them into threes. Those three are called codons. Each codes for one amino acid and all of these is a string of threes which will make a small protein.
Does last mean come before all others?
No, "Last" means come after all others. "First" means come before all others.
What would happen if the very last stop codon of a mRNA molecule was mutated into a regular codon?
That isn't exactly a mutation; it's more like degradation. It would basically mean that mRNA, which is made up of multiple codons, will deteriorate into a codon, which is only 3 nucleic acids combined together. Such corrosion would probably result in the cell breaking the codon like how it normally does mRNA, or it will be absorbed into the nucleus to be combined to form a normal mRNA.
What is the maximum number of amino acids that could be coded for by a sextion of mrna with the sequence guucagaacugu?
A codon is three bases long - so this section of mRNA would have 4 codons; UGA-UUC-AGU-AAC.Each codon relates to a specific amino acid (but several codons can code for the same amino acid, for example both UUU and UUC code for the amino acid Phenylalanine).Normally if you have four codons, such as this section of mRNA, the maximum number of amino acids you could have would be four. However, the first codon in this section, UGA, is actually a STOP codon. This means that when the ribosome reaches this codon, no further amino acids will be joined.This means that no amino acids could be coded for with this section of mRNA. (If the order of the codons was reversed, making the STOP codon last, then the answer would be three).
