GFP - Green Fluorescent Protein - is found naturally in jelly fish. It’s the protein responsible for bioluminescence - the beautiful glow that coverts UV light into a wavelength we can see. This model is 50 million times real life and showcases a beautiful beta barrel surrounding a central chromophore. The chromophore’s atoms are showcased in classic IUPAC colors (red for oxygen, blue for nitrogen and gray for carbon). When the protein folds, three amino acids - serine - tyrosine - glycine - take on new conformations as the molecule is exposed to oxygen in its surrounding environment. These natural conformational changes result in a fluorescent chromophore. Because this molecule self assembles and naturally fluoresces, scientists use it as a small molecular tag by attaching it to other proteins. This allows them to visualize proteins - that now glow green - as they move around the cell. GFP is even small enough to tag on molecules that pass through the nucleus. Realizing the utility of this protein, scientists have designed other molecules that glow red, blue, orange and purple.