Talk:Yeast: Difference between revisions
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Yes. All metabolism releases energy in the form of heat. |
Yes. All metabolism releases energy in the form of heat. |
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Hello, anyone there?''' |
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:Oxygen is required for yeast to grow because it needs to breathe. (or so i have been told) however, if you restrict the presence of oxygen, the sugars get turned into carbon dioxide, which when making beer, tends to make bottles explode. Usually when making wine, if you cork it before all of the sugar has been consumed, it turns into ethanol and carbon dioxide, which leads to a sparking wine - such as champagne. |
:Oxygen is required for yeast to grow because it needs to breathe. (or so i have been told) however, if you restrict the presence of oxygen, the sugars get turned into carbon dioxide, which when making beer, tends to make bottles explode. Usually when making wine, if you cork it before all of the sugar has been consumed, it turns into ethanol and carbon dioxide, which leads to a sparking wine - such as champagne. |
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Revision as of 01:04, 4 July 2005
Does the temperature of the yeast and glucose solution increase during fermentation if in absence of oxygen?
Yes. All metabolism releases energy in the form of heat.
- Oxygen is required for yeast to grow because it needs to breathe. (or so i have been told) however, if you restrict the presence of oxygen, the sugars get turned into carbon dioxide, which when making beer, tends to make bottles explode. Usually when making wine, if you cork it before all of the sugar has been consumed, it turns into ethanol and carbon dioxide, which leads to a sparking wine - such as champagne.
yeast query
what do "obligately arerobic" and "facultatively fermentative" mean?
I know obligately aerobic means it must have oxygen to do its job. Dunno about the other.
Obligately aerobic means that the organism requires oxygen for growth. The principal reason that oxygen is required is to generate energy through oxidative phosphorylation (the tricarboxolic acid cycle and mitochondrial respiration). This is the usual case. Some organisms, such as Saccharomyces cerevisiae, can grow in the absence of oxygen, but they still require oxygen to make certain cell components such as lipids.
"Facultatively fermentative" is not normally used to describe microbial physiology. Rather, the term employed is "facultatively anaerobic". This indicates that the organism is capable of generating metabolic energy through substrate level phosphorylation - generally known as glycolysis.
Yeast and light
Does yeast need light to carry out their life activities?
No. Yeasts are not photosynthetic. They are saphrophytic.
How do I develop a hypothesis?
Start with observations - draw generalizations from the evidence that can be tested experimentally.
- To the best of my knowledge, yeast does not photosynthesize, and does not require light. Bread will rise very happily in the dark. If anything, direct sunlight is probably damaging to yeast. --PJF (talk) 01:02, 8 Apr 2005 (UTC)
- from baking bread as a child and brewing beer as an adult, i seem to remember that yeast is damaged by light.