Admin Can a codon represent more than one amino acid?
Because there are only 20 different amino acids but 64 possible codons, most amino acids are indicated by more than one codon. (Note, however, that each codon represents only one amino acid or stop codon.) Figure 1: In mRNA, three-nucleotide units called codons dictate a particular amino acid.
How many possible amino acids can be encoded by a codon?
Thus, the smallest combination of four bases that could encode all 20 amino acids would be a triplet code. However, a triplet code produces 64 (43 = 64) possible combinations, or codons. Thus, a triplet code introduces the problem of there being more than three times the number of codons than amino acids.
Does a codon never code for more than one amino acid?
Proteins are built from 20 different amino acids, chained together in various combinations. The genetic code is redundant, so that several codons represent the same single amino acid, but there are no ambiguities. There are no examples of a single codon within any genome that represents more than one amino acid.
Which two amino acids are encoded by only a single codon each?
The AUG codon, in addition to coding for methionine, is found at the beginning of every messenger RNA (mRNA) and indicates the start of a protein. Methionine and tryptophan are the only two amino acids that are coded for by just a single codon (AUG and UGG, respectively).
When an amino acid is represented by more than one codon the genetic code is said to be *?
degenerate
Because most of the amino acids are represented by more than one codon, the genetic code is degenerate. Certain amino acids are identified by more than one codons. This phenomenon is called as degeneracy e.g. only AUG codes for methionine and UGG tryptophan.
Which amino acid is encoded by only a single codon?
methionine
Most of the amino acids in the genetic code are encoded by at least two codons. In fact, methionine and tryptophan are the only amino acids specified by a single codon.
How many stop codons are encoded in the genetic code that may be used to terminate translation?
3 STOP codons
There are 3 STOP codons in the genetic code – UAG, UAA, and UGA. These codons signal the end of the polypeptide chain during translation. These codons are also known as nonsense codons or termination codons as they do not code for an amino acid.
When a same triplet codon is code for more than two amino acids it is called?
Three of such bases make up a codon that codes for specific amino acids. There are 64 such codons. But exceptionally, more than one codon may code for the same amino acid e.g. GAA and GAG both code for glutamic acid. This property is called redundancy or degeneracy.