Question

What does it mean to say that the genetic code is degenerate?

Short answer

Short Answer: The genetic code is called degenerate because multiple codons can code for the same amino acid, offering a level of redundancy that helps protect against the impact of mutations and translation errors in the protein sequence.

Step-by-step solution

1. Understanding the Genetic Code

The genetic code consists of triplets of nucleotides called codons. Each codon represents an amino acid or signals the start or stop of a protein synthesis process. There are four different nucleotide bases (adenine, cytosine, guanine, and thymine in DNA, or uracil in RNA instead of thymine), and as a result, there are 4^3 (64) possible codons. However, there are only 20 amino acids that are commonly found in proteins. This indicates that there are more codons than amino acids, leading us to the concept of degeneracy.

2. The Degeneracy of the Genetic Code

The genetic code is said to be degenerate because more than one codon can code for the same amino acid. This means that a single amino acid can be represented by multiple triplets of nucleotides. For example, the amino acid leucine can be coded by six different codons (CUU, CUC, CUA, CUG, UUA, and UUG). Degeneracy is a property of the genetic code that provides redundancy and can help reduce the impact of mutations and translation errors on the resulting protein sequence.

3. Advantages of a Degenerate Genetic Code

The degeneracy of the genetic code has several advantages. One significant advantage is that it offers some protection against the potentially harmful effects of mutations. Point mutations, which involve a change in a single nucleotide, might not have a severe effect on the resulting protein if the mutated codon still codes for the same amino acid. This means that the genetic code can tolerate some errors in DNA replication or transcription without causing significant changes in the protein's amino acid sequence, hence increasing the robustness of the genetic information. In conclusion, the genetic code is considered degenerate because multiple codons can code for the same amino acid. This property of the genetic code provides a degree of redundancy and helps protect against the harmful effects of mutations.