Biology

Microorganisms in Food Production

1,086 Questions

Microorganisms play a vital role in food production through processes like fermentation and bioprocessing. Questions on this topic cover the use of yeast, bacteria, and industrial microbiology. These concepts are important for science sections in various competitive exams.

Alcoholic fermentationDairy beverage productionIndustrial ethanol preparationCitric acid productionBiodigester temperature

Microorganisms in Food Production Questions

Multiple choice biology respiration in plants fermentation cell respiration living organisms and energy production

Which type of fermentation is accompanied by CO$ _2$ evolution?

  1. Alcoholic fermentation

  2. Lactic acid fermentation

  3. Both A and B

  4. None of the above
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The breakdown of glucose to form ethanol and carbon dioxide is known as alcoholic fermentation. This takes place in the cytoplasm of cells. The substrate is glucose which undergoes glycolysis to form pyruvate. This pyruvate is then converted into acetaldehyde after the removal of one carbon and then ethanol is formed along with carbon dioxide.

So, the correct option is 'Alcoholic fermentation'

Multiple choice biology respiration in plants fermentation cell respiration living organisms and energy production

A gas is not produced during

  1. Alcoholic fermentation

  2. Aerobic respiration

  3. Lactic acid fermentation

  4. Both A and B
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation
  • Lactic acid fermentation does not involve decarboxylation and results in the production of lactic acid and NAD$^{+}$.
  • Alcoholic fermentation involves decarboxylation and produces CO$ _{2}$ along with ethanol.
  • Aerobic respiration uses oxygen and glucose to produce CO$ _{2}$ and water as shown below:
          C$ _{6}$H$ _{12}$O$ _{6}$ + 6O$ _{2}$ $\rightarrow$ 6CO$ _{2}$ + 6H$ _{2}$O + energy (heat and ATP)
Multiple choice biology respiration in plants fermentation cell respiration living organisms and energy production

In alcoholic fermentation, CO$ _2$ is evolved during

  1. Decarboxylation of pyruvic acid

  2. Formation of acetaldehyde

  3. Oxidation of acetaldehyde

  4. Both A and B
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Fermentation is a type of anaerobic respiration in which the glucose is converted to release gases, acids and alcohols.

During the alcoholic fermentation of glucose, glycolysis takes place as a result of which pyruvic acid is formed. Pyruvic acid is a three-carbon molecule.
It is then converted into acetaldehyde by losing one carbon dioxide molecule as decarboxylation of pyruvic acid takes place and it forms to 2C acetaldehyde.
So, the correct option is 'Both A and B'

Multiple choice biology respiration in plants fermentation cell respiration living organisms and energy production

Lactic acid fermentation does not produce

  1. ATP.
  2. CO$ _2$ and NADH.

  3. Lactate.
  4. NAD$^+$.
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

In lactic acid fermentation, the 3-carbon pyruvate is converted to the 3-carbon lactic acid. Also NAD$^{+}$ is regenerated in the process, allowing glycolysis to continue to make ATP in anaerobic conditions. Hence lactate and NAD$^{+}$ are the direct products and ATP is the indirect product of lactic acid fermentation. NADH act as a reducing agent here, while CO$ _{2}$ is a product of alcohol fermentation.

Multiple choice biology respiration in plants fermentation cell respiration living organisms and energy production

End product of fermentation of sugars is

  1. Water and carbon dioxide

  2. Alcohol and carbon dioxide

  3. Carbon dioxide

  4. Alcohol
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Fermentation is a type of anaerobic respiration in which the glucose is broken down into pyruvic acid in the absence of oxygen. During fermentation of sugars, this pyruvic acids coverts to a 2C acetaldehyde and then to ethanol and CO₂. All this takes place in the cytoplasm.

So, the correct option is 'Alcohol and carbon dioxide'

Multiple choice biology respiration in plants fermentation cell respiration living organisms and energy production

Fermentation products of yeast are

  1. H$ _2$O + CO$ _2$
  2. Methyl alcohol + CO$ _2$

  3. Methyl alcohol + Water
  4. Ethyl alcohol + CO$ _2$
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Unicellular organisms like yeast undergo an alternate pathway of respiration in which an organic substrate is broken down in absence of oxygen. The end products are alcohol and CO$ _2$. Such a process is called alcoholic fermentation. In Yeast, the fermentation products are ethyl alcohol and carbon dioxide.

So the answer is 'Ethyl alcohol + CO$ _2$'.

Multiple choice biology respiration in plants fermentation cell respiration living organisms and energy production

Conversion of sugar into alcohol during fermentation is due to direct action of

  1. Temperature

  2. Concentration of sugar

  3. Zymase

  4. Microorganisms
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Conversion of sugar to alcohol directly was found in yeast fermentation in which glucose was converted to ethyl alcohol and CO$ _2$. The conversion happens in presence of an enzyme called zymase which is found naturally in yeast. So, the answer is 'Zymase'.

Multiple choice biology life processes in living organisms- part 1 fermentation cell respiration living organisms and energy production

Fermentation produces

  1. Protein and acetic acid

  2. Alcohol and lipoprotein

  3. Alcohol and lactic acid

  4. Ethers and acetones
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Fermentation is a type of anaerobic respiration that occurs in both plants and animals in the absence of oxygen. The end product is ethyl alcohol in plants and lactic acid in animal cells along with release of CO$ _2$ and energy. Fermentation is not as much energy yielding as aerobic respiration.

So the answer is 'Alcohol and lactic acid'.

Multiple choice biology life processes in living organisms- part 1 fermentation cell respiration living organisms and energy production

Fermentation is

  1. Anaerobic respiration

  2. Incomplete oxidation of carbohydrates

  3. Complete oxidation of carbohydrates

  4. None of the above
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Fermentation is a type of anaerobic respiration in which the breakdown of glucose takes place to release acids, alcohols and other gases in absence of oxygen. It takes place in the cytoplasm.

It involves glycolysis which is the breakdown of glucose to form pyruvic acid which can undergo two different pathways to form the lactic acid or ethanol and carbon dioxide.
So, the correct option is 'Anaerobic respiration'

Multiple choice biology respiration in plants fermentation cell respiration living organisms and energy production

Select suitable name for the process
C$ _6$H$ _{12}$O$ _6$ + 2ADP + Pi 2C$ _2$H$ _5$OH + CO$ _2$ + 2ATP

  1. Photorespiration.

  2. Lactate fermentation.

  3. Aerobic respiration.

  4. Alcoholic fermentation.
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

The given process is alcoholic respiration and is done by the yeast in which two molecules of ATP, carbon dioxide and alcohol is released and the process takes place in the absence of oxygen.

So the correct option is 'Alcoholic fermentation.'

Multiple choice biology respiration in plants fermentation cell respiration living organisms and energy production

In which one of the following processes CO$ _2$ is not released

  1. Aerobic respiration in animals.

  2. Alcoholic fermentation.

  3. Lactate fermentation.

  4. Aerobic respiration in plants.
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

In lactic acid fermentation which occurs in the absence of oxygen like fermentation after glycolysis form lactate which gets deprotonated to form lactic acid while in fermentation acetaldehyde converts into alcohol by deprotonation of it.

As lactate does not contain any oxygen in it that is the reason at the end carbon dioxide is not formed.
So the correct option is 'Lactate fermentation'.

Multiple choice biology respiration in plants fermentation cell respiration living organisms and energy production

In alcoholic fermentation, two molecules of glucose produce ethanol and CO$ _2$ respectively

  1. 2 + 2

  2. 3 + 3

  3. 4 + 4

  4. 6 + 6
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

 Alcoholic respiration is done by the yeast in which two molecules of ATP, carbon dioxide and alcohol is released and the process takes place in the absence of oxygen.

$C _6H _{12}O _6 + 2ADP\rightarrow Pi  2C _2H _5OH + CO _2 + 2ATP$
If 2 ATP and $C _2$ is released by molecule. So two glucose will release 4 ATP and $ $CO_2$.
So the correct option is '4 + 4'.

Multiple choice biology life processes in living organisms- part 1 fermentation cell respiration living organisms and energy production

Pasteur effect is __________________.

  1. Stoppage of fermentation in presence of oxygen

  2. Increase of fermentation in presence of oxygen

  3. Decrease in fermentation in presence of oxygen

  4. No effect on fermentation
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The Pasteur effect describes the observation that yeast consumes glucose much faster under anaerobic conditions than under aerobic conditions, effectively inhibiting fermentation when oxygen is present.