DID U KNOW . . . THE ROLE OF YEAST

DID U KNOW . . .
Fresh yeast is a living micro-organism that starts to ferment when flour or sugar are added to it.
This releases carbon dioxide, which makes bread rise. 
Adding sugar to fresh yeast makes it easier to mix into the 
water and encourages it to ferment.
Yeast..
The word "yeast" comes to us from Old English meaning boil, foam, or bubble.
People have used yeast for fermentation and baking throughout history. Yeast, most commonly is used in baking as a leavening agent. This causes the dough to expand or rise as gas forms pockets or bubbles. When the dough is baked, the yeast dies and the air pockets "set", giving  the baked product a soft and spongy texture.
'A leavening agent'  is the  number of substances used in doughs  and batters that cause a foaming action which lightens and softens the  finished product.  The leavening agent starts the  gas bubbles into the dough.  Chemical leavening agents include: like the baking powder and the baking soda. Baking powder is a dry chemical raising agent used to increase the volume and lighten. the texture of baked goods such as muffins, cakes, scones and biscuits. Sodium bicarbonate or sodium hydrogen carbonate is the chemical compound.  appears as a fine powder. It has  many related names such as baking soda,  bread soda, cooking soda, bicarbonate of soda.
Yeast is  tiny, living cells. Active dry yeast and fresh yeast are two types of yeast. Fresh Yeast is the most available form of yeast .  While fresh yeast works very well, it has a short shelf life. Active dry yeast is usually packaged in small individual packages. Too much yeast can cause bread to have a sour flavor. You can buy active dry yeast in bulk, which may keep if it is in an airtight container.
How to Activate Dry Yeast, the water has to be warm. Then add a pinch of granulated sugar and stir with a spoon, mix dry yeast powder also.