Great questions! The answers are actually very interesting. The first fun fact is that fresh flour actually does not contain gluten!! Gluten is a protein made up of two smaller proteins called gliadin and a glutelin. These two smaller proteins do not come together to create gluten until they come in contact with liquid. Once liquid is added and gluten is formed, the gluten molecules start to stick to each other through very strong bonds. Without these bonds formed between gluten molecules, gluten-free dough is not able to bind nearly as strongly. Some gluten-free flours include gum (like guar or xanthum), which helps bring back some of the stickiness lost from taking away gluten.

Congratulations on choosing a good science fair project.I think you will get interesting and useful results.

My Project Scientist, Emin Oroudjev, did research on gluten when he worked in Japan and then again when he worked in my lab, using the atomic force microscope (AFM) to pull on molecules of gluten, to stretch out the molecules and see how they connect to each other.

Gluten is a kind of protein that is found in wheat and some other grains. Gluten molecules form many connections or crosslinks with themselves and other protein molecules. That's why gluten is so good at holding bread and other wheat products together - because the gluten molecules are actually attached to each other, forming a springy network.

Gluten forms lots of crosslinks because it has lots of an amino acid called cysteine. Cysteine has sulfur in it, and the sulfur is in a form that changes when it comes into contact with air. In air, the cysteine's sulfur oxidizes and forms bonds with another sulfur in another cysteine amino acid that is in the same gluten molecule or in another gluten molecule.