What causes the bread dough to rise?

Question

Yeast is used in the backing of bread. Bread dough is usually mixed (yeast, flour, sugar) and then left in a warm environment for about 45 min to "rise." What causes the bread dough to rise? Explain in terms of the chemical reactions occurring. Also, why don't you get drunk when you eat bread?

Answer 1

fermentation. Carbon dioxide is released. Fermentation is normally a 2 step process that recycles NADH to NAD for glycolysis to resume. It's an anaerobic reaction. The final product of yeast fermentation is CO2 and ethanol.

As for why you don't get drunk...i surmise 2 possibilities: the ethanol evaporates in the warm environment OR ethanol is metabolized by yeast cells and converted to acetyl CoA for the krebs cycle (aerobic reaction - so i don't know if this is likely)/ Smooth ER could also uptake the alcohol like liver cells do and detoxify it.

Answer 2

It's not really a chemical reaction. There are some chemicals involved, but the real subject is microbiology. I'll see if I can simplify it.

Yeasts are single celled organisms. They're closest to a fungus. They break down the carbohydrates in flour and sugar, through a cell respiration pathway called fermentation. The carbohydrates break down into glucose, from there into ATP, which is cell energy (there are a bunch of intermediate steps there, check out Wikipedia's entry on glycolysis, it's a pretty good explanation.)

The end result of that fermentation are alcohols, acids, and... Carbon dioxide gas. The carbon dioxide forms bubbles inside the gluten protein matrix of the dough, they get trapped, and it rises. Meanwhile the acids and alcohols provide yummy flavor.

When the bread goes into the oven, the yeasts are killed, and the alcohol evaporates, and you have bread.

I like bread.

Answer 3

In bread production, yeast cells turn carbohydrates into carbon dioxide, which causes the dough to expand or rise, and alcohol, most of which evaporates during baking. The use of potatoes, water from potato boiling, eggs, or sugar in a bread dough accelerates the growth of yeasts.

Answer 4

Yeast and it's reaction thereof. YEAST is a leavening agent used to make bread dough rise. It is a single-cell organism that grows and multiplies as it ferments sugar. The fermentation process produces gases that are trapped in the dough in the form of small bubbles that force the dough to rise into a honeycomb structure.

Answer 5

Bread rising is caused by carbon dioxide that is released from yeast cells within the dough. When yeast perform anarobic fermentation, the two waste products are Carbon dioxide and alchohol, so CO2 causes the dough to rise.

Answer 6

Yeast is a living organism when you activate it with warm water and feed it sugar and carbohydrates it gives off CO2 (carbon dioxide) which makes the bread rise. The baking process stops the fermentation

Actually, Ancient Egyptians did make their beer from bread and honey.

Answer 7

Everybody always thinks its the yeast, but that isn't true. Flat, unleavened bread also has yeast, so what's the difference? The answer is that kneading the bread brings oxygen in, causing the bread to rise as its heated.

Answer 8

The yeast release CO2 after eating the sugar. C6H12C6 -> CXOH + CO2.

Answer 9

not exactly what you wanted, however.......the bread rises because the yeast gets hot, and therefore expands...causing the bread to rise...And the reason you don't get drunk when you eat bread is because it is used in two different ways...First, for bread, it is heated up...In alcoholic drinks, it is set up, and over time it starts to furment (or however you spell it), and through furmentation, alcohol is formed.

Answer 10

yeast. and look at the chemical equation of fermentation of yeast