A mutation is a permanent change in a DNA sequence. Some mutations can affect the protein a gene codes for.
The short DNA sequence below comes from the middle of a much longer gene. Change the DNA letters and see how it affects the resulting mRNA and protein. How do I edit the gene?
How do I edit the gene?
- Point mutation (change one DNA letter)
- Select a base
- In the menu that pops up, choose the letter you want to change it to
- Deletion mutation
- Select a base
- In the menu that pops up, choose the trashcan icon (see left image)
- Insertion mutation
- Select an arrow (between bases)
- In the menu that pops up, choose which base you want to add (see right image)
What are the colors on the amino acids showing?
Amino acids are different colors to start. These colors have to do with each amino acid’s chemical properties:
red = acidic (positive)
blue = basic (negative)
grey = hydrophobic
yellow = sulfur molecules; these can form bonds with each to make disulfide bridges, which help to stabilize a protein's three-dimensional structure
After you make a mutation, color highlights appear around some amino acids. These colors indicate the type of change you made:
green = silent mutation (the amino acid didn't change)
red = amino acid substitution (the amino acid changed)
blue = frame shift (multiple amino acids changed)
Genes are instructions for building proteins, and they are written in a literal code. To read a gene, a cell first makes an mRNA copy. Then it reads the mRNA letters to build a protein.
For a refresher on how cells read genes, visit Transcribe and Translate a Gene .