Talk:Yeast

Does the temperature of the yeast and glucose solution increase during fermentation if in absence of oxygen?

Hello, anyone there?

Oxygen is required for yeast to grow because it needs to breath. (or so i have been told) however, if you restrict the presence of oxygen, the sugers get turned into carbon dioxied which when your making wine, tends to make bottles or corks explode. usualy when making wine, if you cork it, the suger tends to turn into carbon dioxied, and then if you open the cork to air it every day. you will get a sparkling wine because (I assume) the carbon dioxied becomes bound to the water for lack of an exit.

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? How do I develop a hypothesis?

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.