What are the 4 nucleotides that makeup DNA? What happens if one of these nucleotides is swapped for another?
The four nucleotides that make up DNA are adenine (A), thymine (T), cytosine (C), and guanine (G).
If one of these nucleotides is swapped for another, the genetic code can be altered, leading to a mutation. The effect of this mutation depends on where it occurs in the DNA sequence and the specific nucleotide substitution.
Sometimes, a substitution may have no impact and no visible effect on the organism. This is because the genetic code is degenerate, meaning that more than one codon can code for the same amino acid. In such cases, the substituted nucleotide may result in the same amino acid being incorporated during protein synthesis.
However, in other cases, a nucleotide substitution can lead to detrimental alterations in protein structure or function. This can result in genetic disorders, diseases, or changes in physical traits. For instance, if a nucleotide substitution occurs in a critical region of a gene that encodes an enzyme, it may disrupt or impair the enzyme's activity, leading to a metabolic disorder.
In certain circumstances, nucleotide substitutions can also be advantageous. They can introduce variations that provide a selective advantage to an organism, allowing it to adapt and survive in changing environments. These substitutions can play a significant role in the process of evolution.