Tag: respiration in plants

Questions Related to respiration in plants

Choose the correct answers from the alternatives given :
Which of the following engage in lactate fermentation?

  1. Lactobacillus cells

  2. Muscle cells

  3. Sulphate-reducing bacteria

  4. Both (a) and (b)


Correct Option: D
Explanation:
  • Lactobacillus baterial are used for the preparation of curd from the milk. These bacterial cells perform the reaction of lactic acid fermentation where they use the lactose in the milk as substrate converting to lactic acid of curd.
  • Muscle cells when they undergo go excessive physical work and there is not enough oxygen to undergo aerobic respiration so they also perform the process of lactic acid fermentation forming lactic acid in the muscles but excessive formation of lactic acid will lead the muscle to go into fatigue condition where the muscle will be no longer able to perform any physical function for atleast some time.
  • Therefore the answer option 'Both (a) and (b)' is correct.

Choose the correct answers from the alternatives given :
In alcoholic fermentation is the final acceptor of the electrons stripped from glucose. 

  1. sulphate

  2. pyruvate

  3. acetaldehyde

  4. oxygen


Correct Option: C
Explanation:

  • 2 enzymes are present in the alcoholic fermentation of pyruvate they are decarboxylase and alcoholic dehydrgenase.
  • The pyruvate is first converted to acetaldehyde in the presence of decarboxylase enzyme.
  • This acetaldehyde is the final acceptor of electrons and it converts the NADH to NAD so that the process of glycolysis can continue without hinderance.
  • This acetaldehyde is then converted to ethanol in presence of alcohol dehydrogenase.
  • Therefore here the acetaldehyde or the pyruvate are the final acceptor of electron.
  • Therefore options 'pyruvate' and 'acetaldehyde' both can be correct answers.






The end products of fermentation are

  1. $O _2$ and ethyl alcohol

  2. $O _2$ and acetaldehyde

  3. $CO _2$ and ethyl alcohol

  4. $CO _2$ and acetaldehyde


Correct Option: C
Explanation:

Fermentation is the process of partial breakdown of glucose into ethyl alcohol or lactate. It is an anaerobic process. Fermentation takes place through the two types - lactic acid fermentation and alcohol fermentation.

 Name of process  End products
 Lactic acid fermentation   Lactate
 Alcohol fermentation  Ethyl alcohol + CO2

So, the correct answer is ' COand ethyl alcohol '
.



During alcoholic fermentation by yeast two molecules of glucose produce.

  1. $2$ molecules of ethanol $+2$ molecules of $CO _{2}$

  2. $4$ molecules of ethanol $+ 4$ molecules of $CO _{2}$

  3. $6$ molecules of ethanol $+ 6$ molecules of $CO _{2}$

  4. $3$ molecules of ethanol $+ 3$ molecules of $CO _{2}$


Correct Option: B
Explanation:

Alcoholic fermentation is a process of anaerobic respiration in which 2 molecule of glucose is converted to -
4 molecules of ethanol,
4 molecules of carbon dioxide,and
4 ATP.
So, the correct option is '4 molecules of ethanol + 4 molecules of CO$ _2$'.

A test tube containing molasses solution and yeast is kept in a warm place overnight. The gas collected from this mixture
  1. Extinguishes the flame

  2. Bursts into flame when ignited

  3. Turns lime water milky

  4. Both (a) and (c)


Correct Option: D
Explanation:
Yeast do anaerobic fermentation by consuming sugar and forming ethanol and $CO _2$.  As Molasses mainly contain sugar, yeast will do anaerobic fermentation of the molasses and forms $CO _2$ gas as a by-product. 
This $CO _2$ gas can (i) extinguishes the flame, and (ii) Turns lime water milky.
So, the correct answer is (D).

Alcoholic fermentation is carried out by

  1. Saccharomyces.

  2. Lactobacillus.

  3. Clostridium.

  4. Aspergillus.


Correct Option: A
Explanation:

Saccharomyces is used in fermentation is alcohol. Saccharomyces will be grown in anaerobic conditions same as growth takes place in aerobic conditions.

So the correct option is 'Saccharomyces.'

Formation of lactic acid from pyruvate requires

  1. Decarboxylation

  2. Reduction

  3. Oxidation

  4. Hydration


Correct Option: B
Explanation:

Pyruvate + NADH $\rightarrow$ Lactic acid + NAD$^{+}$
Muscle cells convert pyruvate into lactate. Here, pyruvate (a metabolite of glucose) is reduced to lactic acid by accepting electrons from NADH, which oxidizes NADH back to NAD$^{+}$ to allow glycolysis to continue under anaerobic conditions. 

Alcoholic fermentation occurs in the presence of

  1. Zymase.

  2. Amylase.

  3. Invertase.

  4. Maltase.


Correct Option: A
Explanation:

The fermentation process is catalyzed by enzyme Zymase which converts sugar to ethanol and carbon dioxide.

So the correct option is 'Zymase.'

Alcoholic fermentation uses

  1. Ribosomes

  2. Golgi bodies

  3. Mitochondrial enzymes

  4. Cytoplasmic enzymes


Correct Option: D
Explanation:

The production of ethanol is called alcohol fermentation. The very first reaction catalyzed by a cytoplasmic enzyme, pyruvate decarboxylase.

So the correct option is 'Cytoplasmic enzymes.'

Which enzyme converts glucose into alcohol?

  1. Invertase

  2. Lipase

  3. Zymase

  4. Diastase


Correct Option: C
Explanation:

Fermentation process is catalyzed by enzyme Zymase which converts sugar to ethanol and carbon dioxide.

So the correct option is 'Zymase.'