It is because of the yeast.
The yeast cells in bread dough ferment sugars and produce gas (carbon dioxide). This makes the dough rise.
No, bread would not be bread or bread dough without flour, and it definitely would not rise.
yes
Yeast.
Carbon dioxide
Your bread dough will rise then fall on the second rise if you allow it to sit too long. When left to rise too long, the yeast will consume all of the available sugar in the dough, resulting in fallen bread dough.
it doesn't rise up because the yeast makes the bread expand.
To make overnight rise bread, mix the dough ingredients and let it rise in the refrigerator overnight. The slow rise develops flavor and texture. Shape the dough in the morning, let it rise again, then bake as usual.
yeast is a microscopic organism that makes bread rise
No, air by itself does not make bread rise. In yeast dough, the micro organisms (yeast) consume sugars in the dough and produce gas. The gas bubbles are trapped in molecules of protein in the dough called gluten. These gas bubbles expand and cause the dough to rise. When the dough is baked, the heat makes the gas bubbles expand further producing soft delicious bread.
Using a KitchenAid dough hook for kneading bread dough can save time and effort compared to kneading by hand. It helps to develop gluten in the dough, resulting in a better texture and rise of the bread.
Yeast turns some of the sugar in bread dough into alcohol and carbon dioxide. The carbon dioxide fills the bread with a lot of little bubbles. That makes it easy to eat. Without yeast bread would be like eating raw spaghetti.