In the genetic code dictionary, how many codons are used to code for a...
Out of a total of 64 codons, 3 codons do not make any sense. Hence only 61 codons are used in the formation of the 20 essential amino acids (polypeptides).
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In the genetic code dictionary, how many codons are used to code for a...
The genetic code is the set of rules by which information encoded in genetic material (DNA or RNA sequences) is translated into proteins. It is a triplet code, meaning that each three-nucleotide sequence (codon) corresponds to a specific amino acid or a stop signal.
There are a total of 64 possible codons in the genetic code, consisting of all possible permutations of the four nucleotides (adenine, cytosine, guanine, and thymine/uracil) taken three at a time. These codons can code for the 20 essential amino acids and three stop signals.
To determine the number of codons used to code for the 20 essential amino acids, we need to subtract the number of stop codons from the total number of codons.
- Total number of codons = 64
- Stop codons = 3 (UAA, UAG, UGA)
Therefore, the number of codons used to code for all the 20 essential amino acids is:
64 - 3 = 61
Hence, the correct answer is option D, 61.
It is worth noting that the genetic code is degenerate, which means that multiple codons can code for the same amino acid. For example, the amino acid leucine is coded by six different codons (UUA, UUG, CUU, CUC, CUA, and CUG). This redundancy provides some level of error correction during protein synthesis and allows for variations in DNA sequences without affecting the resulting protein.
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