Please answer this fully I need to really understand this an

Please answer this fully.

I need to really understand this and this question:

It is possible to isolate yeast (Saccharomyces cerevisiae) that have completely lost their mitochondrial DNA and thus their ability to produce functional ATP synthase. They grow slower than regular yeast, but they do grow. Could you use these yeast instead of regular yeast to make bread? Why or why not? Could you use them instead of regular yeast to make beer? Why or why not?

PLEASE answer this fully so I could understand it if its possible

Solution

yes it is possible to produce yeast cells without mitochondria and the cell can still survive through anerobic respiration

fermentation reaction occurs in the cytoplasm

both bread and beer depend on the alcohol fermentation reaction of the yeast

the bread requires the released CO₂ for leavening the dough and beer requires the ethanol that is generated through the reaction

howver mitochondria free cells cannot be used for bread or beer fermentation

the reason is

glycolysis:

glucose -----> 2pyruvate+2ATP+2NADH

when there is a mitochondria the NADH enters into it and continues the electron transfer chain reaction to regenerate NAD+

pyruvate decarboxylase synthesized by mitochondria is essential for ethanol fermentation

pyruvate +pyruvate decarboxylase -----> acetaldehyde + CO₂

this acetaldehyde will be reduced to ethanol using NADH

acetaldehyde + NADH ------> ethanol +NAD⁺

in the abscence of mitochondria the pyruvate will soon be converted to lactic acid than ethanol thus giving a sour taste to the bread or beer that is made

this reaction is necassary for regeneration of NAD⁺

these yeasts can however be used in making sourdough for a specific variety of bread as lactic acid is more important in making the sour dough along with CO₂