Like all batteries, eventually it gets depleted and needs to be replaced; this can be expected to happen after 5-10 years, depending on system usage. CMOS checksum error (and similar messages) or the system clock being reset are classic signs of the battery having been depleted. The BIOS settings contain several system-critical values.
In order to grow, yeast need glucose (C 6 H 12 O 6) or sucrose (table sugar, C 12 H 22 O 11), water (H 2 O) and warm temperatures. As yeast digest sugar, they turn into alcohol. In the process they give off carbon dioxide (CO 2) gas. The alcohol dissolves in the water and the gas escapes into the air. Yeast is used to make bread.
The purpose of any leavener is to produce the gas that makes bread rise. Yeast does this by feeding on the sugars in flour, and expelling carbon dioxide in the process.While there are about 160 known species of yeast, Saccharomyces cerevisiae, commonly known as baker's yeast, is the one most often used in the kitchen. Yeast is tiny: Just one gram holds about 25 billion cells.ith no place to go but up, this gas slowly fills the balloon. A very similar process happens as bread rises. Carbon dioxide from yeast fills thousands of balloonlike bubbles in the dough. Once the bread has baked, this is what gives the loaf its airy texture.