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 introduction to microbiology food production and microorganisms microbial products - food, medicines and industrial products uses of microorganisms commercial use of microorganism microbes in household and industry

Baker's yeast is?

  1. S. cerevisae

  2. S. ludwingii

  3. S. octosporus

  4. Schizosaccharomyces
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The yeast most commonly used for leavening bread is Saccharomyces cerevisiae, the same species used for brewing alcoholic beverages. This yeast ferments some of the carbohydrates in the flour, including any sugar, producing carbon dioxide. 

So the correct option is 'S. cerevisiae'.

Multiple choice biology introduction to microbiology food production and microorganisms microbial products - food, medicines and industrial products uses of microorganisms commercial use of microorganism microbes in household and industry

During its formation, bread becomes porous due to CO$ _2$ released by

  1. Protozoans

  2. Bacteria

  3. Yeast

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

Bread is prepared from the dough, which is fermented using baker's yeast ( Saccharomyces cerevisiae ). The puffed-up appearance of dough is due to the production of carbon dioxide during fermentation. Carbon dioxide gas along with ethyl alcohol evaporate during baking, making bread porous and soft. 

So, n2
So, the correct answer is 'Yeast'

Multiple choice biology introduction to microbiology food production and microorganisms microbial products - food, medicines and industrial products uses of microorganisms commercial use of microorganism microbes in household and industry

Which one is used for preparation of bread?

  1. Lactobacillus

  2. Streptobacillus

  3. Aspergillus

  4. S.cerevisiae
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Saccharomyces cerevisiae, commonly known as baker's yeast, is the primary microorganism used in the bread-making process for leavening.

Multiple choice biology introduction to microbiology food production and microorganisms microbial products - food, medicines and industrial products uses of microorganisms commercial use of microorganism microbes in household and industry

Mostly bread is semi-sweet in taste due to.

  1. Yeast

  2. Remnants of alcohol

  3. Sugar

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

In the making of bread both carbon dioxide and alcohol are trapped by the dough and both are expelled from the dough by the heat of baking. So, the bread tastes semi-sweet.

So, the correct answer is 'Remnants of alcohol'.

Multiple choice biology food production food production and microorganisms microbial products - food, medicines and industrial products uses of microorganisms

Commercial source of manufacture of cheese especially for giving flavour to it, its from _____________.

  1. Citrus fruit

  2. Aspergillus

  3. Penicillium

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

Various bacteria, such as Propionibacterium and others, are used in the cheese-making industry to develop specific flavors and textures during the ripening process.

Multiple choice biology food production food production and microorganisms microbial products - food, medicines and industrial products uses of microorganisms

Which is wrongly matched 

  1. Clostridium butylicum - Lactic acid

  2. Aspergillus hiner - Citric acid

  3. Yeast - Statins

  4. Acetobacter aceti - Acetic acid
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Clostridium butylicum is used to produce butyric acid. Lactic acid is produced by Acetobacter.

So, the correct option is 'Clostridium butylicum - Lactic acid'

Multiple choice zoology skeleton and movements features of a muscle muscle features muscle contraction and its effects
Select the incorrectly matched pair.
  1. End products of alcoholic - Ethanol + ${CO} _{2}$
  2. End products of lactic acid fermentation - Lactic acid + ${CO} _{2}$

  3. Glycolysis - Cytoplasm

  4. Key product of glycolysis - Pyruvic acid
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation
Lactic acid fermentation occurs in lactic acid bacteria (e.g., Lactobacillus), some fungi and muscles. In lactic acid fermentation, pyruvic acid produced in glycolysis is directly reduced by NADH to form lactic acid. No ${CO} _{2}$ is produced. The enzyme is lactate dehydrogenase which requires FMN and ${Zn}^{2+}$.

$Pyruvic \,\,acid+NADH\xrightarrow[FMN,{Zn}^{2+}]{Lactate \,\,denydrogenase}Lactic \,\,acid+{NAD}^{+}$

So the correct answer is 'End products of lactic acid fermentation - Lactic acid + ${CO} _{2}$'.
Multiple choice biology chemical coordination in plants ethylene plant hormones plants and animal hormones

Ethylene is involved  in .........................

  1. Aerobic respiration

  2. Anaerobic respiration

  3. Climacteric respiration

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

Ethylene is an important natural plant hormone, used in agriculture to force the ripening of fruits. Binding of ethylene to the receptors unleashes a signaling cascade that leads to activation of transcription factors and the turning on of gene expression. The climacteric is a stage of fruit ripening associated with increased ethylene production and a rise in cellular respiration.

Multiple choice biology chemical coordination in plants ethylene plant hormones plants and animal hormones

Ethylene is connected with

  1. Aerobic respiration

  2. Climacteric respiration

  3. Anaerobic respiration

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

Ethylene is a plant hormone. It is also called as ripening hormone as it is responsible for ripening of fruits. Fruit ripening is accompanied by increase rate of respiration. The climacteric respiration occurs during fruit ripening which is associated with increased ethylene production. Due to increased respiration, complex carbohydrates are broken down into simpler sugars and cell wall becomes soft. 

Thus, the correct answer is option B.

Multiple choice zoology respiratory system do plants breathe? plant respiration respiration-plants

When yeast and sugar solution are left to stand without oxygen for some time they develop a characteristic smell due to the production of new compound, which is

  1. Ethanol

  2. Ammonia

  3. Carbondioxide

  4. Sodium carbonate
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
When yeast has both sugar and oxygen available to it, it undergoes aerobic respiration to produce energy, water and carbon dioxide. In the absence of oxygen, yeast switches over to a process called anaerobic respiration. During which, sugar is fermented to produce energy, carbon dioxide, and ethanol. Yeast that produces ethanol from the sugar has a characteristic smell and this process is generally used to ferment wine.
So, the correct answer is 'Ethanol'.
Multiple choice zoology respiratory system do plants breathe? plant respiration respiration-plants

The product obtained in the anaerobic respiration of yeast is 

  1. Lactic acid

  2. Pyruvic acid

  3. Ethanol

  4. Acetic acid
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation
The following reaction is of anaerobic respiration in yeast-      
                     zymase
 C₆H₁₂O₆  -------------------->  C₂H₅OH + 2CO₂  +  50KJ energy
                        yeast

Here, the ethanol is a by-product of anaerobic respiration. It takes place in the cytoplasm of the cell.

Multiple choice zoology respiratory system do plants breathe? plant respiration respiration-plants

Which one is product of aerobic respiration?

  1. Malic acid

  2. Ethyl alcohol

  3. Lactic acid

  4. Pyruvic acid.
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Glucose breakdown into pyruvic acid in the absence of oxygen and in the absence of oxygen pyruvic acid is converted into lactic acid even yeast in converted to ethyl alcohol in no-oxygen.

So the correct option is 'Malic acid'.

Multiple choice zoology respiratory system do plants breathe? plant respiration respiration-plants

Which can readily respire without oxygen?

  1. Anabaena

  2. Saccharomyces

  3. Mushroom

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

Yeast possesses good fermentation potential in the absence of oxygen. Saccharomyces grow anaerobically (without oxygen) same as it grows in aerobically (with oxygen).

So the correct option is 'Saccharomyces'.

Multiple choice zoology respiratory system do plants breathe? plant respiration respiration-plants

The respiratory process of yeast is

  1. Rarely anaerobic

  2. Anaerobic

  3. Purely aerobic

  4. Both aerobic and anaerobic
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

A unicellular organism like yeast can carry out both aerobic as well as anaerobic respiration depending on the environmental conditions. Anaerobic respiration is usually alcoholic fermentation and the end products are ethanol and carbon dioxide. Aerobic respiration produces CO$ _2$ and H$ _2$O as end products.

So, the correct answer is 'Both aerobic and anaerobic'.

Multiple choice biology improvement in food resources crop variety improvement improvement if crop varieties improvement in crop variety

What makes the bread soft and fluffy?

  1. Finely ground flour

  2. Alcohol given off during fermentation of sugar

  3. Carbon dioxide gas given off during fermentation of sugar

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

Yeast ferments the sugar present in the dough into carbon dioxide. The ${ CO } _{ 2 }$ released from the yeast fills the dough and increases its volume. Once, the bread has baked, the heat causes the bubbles to break and makes the bread light and fluffy.