It keeps them puffy like baking soda and it is the whole thing basically. It just NEEDS flour
browning
During baking the heat from the oven cooks the flour, and depending upon the ingredients used, the temperature and the duration of cooking you get a bread, cakes or biscuits as the end product
The sensory function of flour is to provide a solid textture for the product and provide structure for the food.
If you just used whole wheat flour, the biscuits would be very heavy and coarse.
Most likely you mean 'from scratch' cooking which means taking ingredients that aren't previously prepared and adding them together to create a dish. For example, biscuits made from Bisquick are not from scratch but biscuits where I measured out the flour, baking powder, etc. are
Egg functions as food-glue and biscuits are a great food for demonstrating it. Go ahead and make biscuits with and without the egg. You will see that the no-egg batch will be very crumbly and will fall apart too easily to be useful for much.
Yes they can
cause if you dont then it wont be a bisciut because the flour and the baking powder are the main ingredients for making bisciuts.
It is an acidic leavening agent - it reacts with anything alkaline in the recipe, releasing CO2 and making the mixture rise.
Based on a regular, full recipe that uses 2 cups of flour, and makes 13 - 16 biscuits, a single biscuit contains 1.2 to 1 ounce of flour by volume and .85 to .69 of an ounce by weight.
Shortbread biscuits Shortbread biscuits
A suitable flour substitute for roux in cooking is cornstarch.