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Microbiology · Chapter 7

Point Mutations: One Base, One Protein

A change in a single DNA base can ripple all the way to the protein — sometimes silently, sometimes catastrophically. In microbes these point mutations are a major source of spontaneous antibiotic resistance. Tap each type to watch one codon change rewrite the protein.

Reference mRNA → protein

Reading the strip: each box is one codon (3 bases) with its amino acid below. Amino acids: green = reference, coral = altered, STOP = chain ends early.
Point mutationstap a type to explore
One base at a timeThe DNA is read three bases at a time. A point mutation changes just one base — but where it lands, and whether the codon still makes sense, decides everything downstream. Because the genetic code is degenerate (most amino acids have several codons), not every change matters.