White sugar, brown sugar, honey, and molasses may all be interchanged equally. Most artificial sweeteners may not be substituted in bread making as they are proteins and cannot be fermented. Salt - Salt affects the activity of yeast. Without salt, the yeast acts very rapidly and peters out too quickly. Too much salt will stunt yeast activity.
Salt adds flavor and strengthens the dough structure.
Flour - Dough structure is formed from the protein in wheat flour. Other grains can be ground into flour, but wheat is the only grain that contains a sufficient amount of the type of protein that forms gluten. When the flour is mixed with other ingredients, the protein comes in contact with the liquids and becomes gluten. Kneading the dough develops an interlocking network of elastic gluten strands which hold the dough together. Fats and liquid sweeteners also add moisture but are considered in their own categories.