Courses
Courses for Kids
Free study material
Offline Centres
More
Store Icon
Store
seo-qna
SearchIcon
banner

The fermentation of glucose by yeast normally yields
A.Lactic acid, CO2 and 2ATP
B.Alcohol, CO2 and 36ATP
C.Alcohol, CO2 and 2ATP
D.CO2, H2O and 36ATP

Answer
VerifiedVerified
402.9k+ views
like imagedislike image
Hint: Glucose is a type of carbohydrate, it is made up of carbon, hydrogen and oxygen atoms.
Fermentation is defined as the incomplete oxidation of glucose carried out in the absence of oxygen known as anaerobic condition.

Complete answer:
Fermentation of glucose is a type of metabolic reaction which involves many prokaryotic organisms and unicellular eukaryotes like yeast.
Anaerobic conditions are required for the fermentation process to complete because presence of oxygen causes complete oxidation of glucose and yields different products like pyruvate and energy.
Glucose molecules undergo a 9 step reaction to form pyruvate as in the case of glycolysis to and 2ATP.
seo images

After glycolysis each molecule of glucose produced two molecules of pyruvate, 2ATP and 2NADH.
After the formation of pyruvate, fermentation enzymes act on it to yield different products in the absence of oxygen.
Pyruvate molecule undergoes decarboxylation process in the presence of pyruvate decarboxylase to yield two molecules of acetaldehyde, two molecules of carbon dioxide and NADH.
2C3H4O3ez2CH3CHO+2CO2+2NADH
Where C3H4O3 is pyruvate
CH3CHO Is acetaldehyde molecule
CO2 Is carbon dioxide
NADHEnergy molecule
(ez) Is enzyme pyruvate decarboxylase
Acetaldehyde form in the step further undergoes chemical reaction in the presence of enzyme acetaldehyde dehydrogenase to finally form two molecules of ethanol by utilizing the energy formed in earlier step.
2CH3CHOez2CH2OH+2NAD+
Where (ez) is an enzyme acetaldehyde dehydrogenase
C2H5OH Is ethanol or alcohol
Hence, after completion of fermentation process one glucose molecule finally forms Alcohol, CO2 and 2ATP so option (D) is correct .
During fermentation a very small amount of energy (<7%)is released from one molecule of glucose.

Note:
Glucose is commonly known as sugar because of its sweet taste. Glucose comes under the category of monosaccharide because it can not be further hydrolyzed to yield a smaller unit.
Yeast present in the reaction during fermentation undergoes self-death when concentration of alcohol reaches (13%)
Latest Vedantu courses for you
Grade 11 Science PCM | CBSE | SCHOOL | English
CBSE (2025-26)
calendar iconAcademic year 2025-26
language iconENGLISH
book iconUnlimited access till final school exam
tick
School Full course for CBSE students
PhysicsPhysics
ChemistryChemistry
MathsMaths
₹41,848 per year
Select and buy