When making something like flour tortillas, which don't call for yeast in the dough, it's called for to have the dough rest for about an hour before forming to a tortilla and cooking. What is the purpose of resting a flour dough without yeast?
Flour is essentially dried ground wheat, and when you mix it with water, it takes a long time for the flour to absorb water and soften. This is necessary for the gluten to have a chance to connect, so that you have a streachy dough.
During the so-called autolyse step, proteases go to work snipping up the gluten:
Experimental evidence has been obtained to support the hypothesis that gluten softening is a result of peptide bond scission catalysed by proteolytic enzymes. Extensive softening of gluten is observed even though very few peptide bonds are broken. These effects will probably be more noticeable if the wheat from which the flour is milled has begun to germinate.
Redman, D. G. (1971). Softening of gluten by wheat proteases. Journal of the Science of Food and Agriculture, 22(2), 75-78.