Yes, actually it does.
The yeast cells in bread dough ferment sugars and produce gas (carbon dioxide). This makes the dough rise.
When yeast dough rises, the process is called rising or leavening. The first phase of rising, when yeast is dissolved in warm water and sugar until it foams, is called proofing.
chemical
The gas produced by yeast during the fermentation process when bread rises is carbon dioxide. As yeast metabolizes sugars, it releases carbon dioxide and alcohol, causing the dough to expand and rise. This gas creates the characteristic airy texture of the bread.
The gas released by yeast, CO2, creates bubbles, as the bubbles expand in the dough, the bread rises. As the bread bakes, the bubbles set and give the bread its light, airiness.
Because it is. as you know bread is yeast therefore yeast rises to the top and expands leaving the bread bigger than it was. Source: www.eatmypooanddrinkmypee.co.uk
Bread is traditionally made from various products combined with copious amounts of yeast. This concotion is then placed into an oven, and the yeast rises to yield bread.
A chemical change
carbon dioxide
Bread rises more quickly when it's warm, so it will rise a noticeable amount in just a few minutes in the oven, until it gets hot enough (inside the bread) to kill the yeast, at which point it stops rising.
Yeast is a natural fungus with starts to grow when temperature rises, therefore making bread larger (for example). Yeast is most commonly used in bread making, helping it to rise.
Active dry yeast and bread machine yeast are both types of yeast used in bread making, but they have some differences. Active dry yeast needs to be dissolved in water before use, while bread machine yeast can be mixed directly with dry ingredients. Active dry yeast typically requires longer rising times, while bread machine yeast is designed for quicker rising in bread machines. Using the wrong type of yeast can affect the rising and texture of the bread, so it's important to use the correct type specified in the recipe for best results.