Why does yeast bread get warm as it rises?
a. the yeast moves around and creates friction
b. the bread doesn't get warm, that's a misconception
c. the yeast generate heat as they metabolize sugar
d. as carbon dioxide bubbles expand the bread, they create heat
- Anonymous1 decade agoFavorite Answer
c. is the right answer
a) and d) are true too, but insignificant compared to a. ( very little amount of energy/ temperature compared to yeast metabolic)
- 1 decade ago
Well it looks like the answer has to be C. because the bread would only rise when the yeast is releasing Carbon Dioxide and Ethanol while it is metabolizing. And I am assuming that when the yeast is going through the process of fermentation, it is gathering and releasing energy or "ATP" .
So if the Saccharomyces cerivisiae ( Fungal yeast ) is producing the carbondioxide as a product of its metabolism then it is therefore releasing heat. I would say the best answer would be C. The CO2 doesnt generate heat but the metabolism of the yeast does because of production of ATP