Question

The correct sequence of anaerobic reactions in yeast is

(a) $Glucose\stackrel{cytoplasm}{\to }Pyruvate\stackrel{mitochondria}{\to }Ethanol+Carbondioxide$
(b) $Glucose\stackrel{cytoplasm}{\to }Pyruvate\stackrel{cytoplasm}{\to }Lacticacid$
(c) $Glucose\stackrel{cytoplasm}{\to }Pyruvate\stackrel{mitochondria}{\to }Lacticacid$
(d) $Glucose\stackrel{cytoplasm}{\to }Pyruvate\stackrel{cytoplasm}{\to }Ethanol+Carbondioxide$

Answer 1

(d) $Glucose\stackrel{cytoplasm}{\to }Pyruvate\stackrel{cytoplasm}{\to }Ethanol+Carbondioxide$

In anaerobic respiration when oxygen is not available, pyruvate is converted to ethanol a 2 carbon molecule. The first step is the breakdown of glucose, a six-carbon molecule, into a three-carbon molecule called pyruvate. This process takes place in the cytoplasm. Further, the pyruvate may be converted into ethanol and carbon dioxide. This process takes place in yeast during fermentation. Since this process takes place in the absence of air (oxygen), it is called anaerobic respiration.