Final answer:
There are 64 possible codons that can be formed from different combinations of nitrogen bases, which encode for the 20 common amino acids found in proteins. The redundancy in the genetic code allows for some amino acids to be coded by more than one codon, providing robustness against mutations.
Step-by-step explanation:
Total Combinations of Nitrogen Bases and Amino Acids
The question revolves around how many total amino acids can be produced by different combinations of nitrogen bases. To start with a basic understanding, the nitrogen bases in mRNA are adenine (A), uracil (U), cytosine (C), and guanine (G). If each nitrogen base represented an amino acid, we would have only four amino acids. However, with groups of three bases, called codons, the number of different possible combinations is 4³ or 64 possible codons. This is more than sufficient to code for all 20 common amino acids found in proteins. To clarify, three nucleotides form a codon and each codon corresponds to an amino acid or a stop signal during protein synthesis. Despite there being 64 possible codons, there are only 20 common amino acids because some amino acids are encoded by more than one codon.
An important aspect of this redundancy is the degeneracy of the genetic code, which allows for multiple codons to encode a single amino acid. This provides a buffer against mutations in the DNA sequence, as a change in one nucleotide may not necessarily change the amino acid if the new codon still translates to the same amino acid. The genetic code is thus able to maintain the proper synthesis of proteins even with minor changes to the mRNA sequence.
Therefore, with the genetic code's combinatorics, a large diversity of proteins can be synthesized due to the 64 possible codons directing the arrangement of 20 amino acids in numerous sequences, leading to an immense variety of protein structures and functions.